Assorted Experience

Well, the right click (alt fire) on the suppressed pistol activates some magic device that can temporarily knock out a light - for about 10s or so. Why did I have to search on the internet and track down vague clues until I hit this page and found out for sure? Shouldn't there  be a manual somewhere? UPDATE: I gotta read the notes on the equipment screen more carefully... UPDATE2: The manual is useful. Save trees/animal skins, don't print it out.

A good guide is available here File:  /Library/StartupItems/RRiki/StartupParameters.plist : {  Description = "RRiki server";  Provides    = ("RRiki");  Uses        = ("Ruby");  OrderPreference = "Last";  Messages =  {   start = "Starting RRiki server";   stop = "Stopping RRiki server";   restart = "Restarting RRiki server";  }; } File: /Library/StartupItems/RRiki/RRiki #!/bin/sh ## # RRiki service startup script ## . /etc/rc.common StartService () {     ConsoleMessage "Starting RRiki"     cd /Users/kghose/Source/Rriki2/     /usr/local/bin/thin start -eproduction -d } StopService () {     ConsoleMessage "Stopping RRiki"     cd /Users/kghose/Source/Rriki2/     /usr/local/bin/thin stop  } RestartService () {     ConsoleMessage "Restarti...

Now using thin rather than mongrel. Seems to be fast and responsive and most importantly installs without errors.

in partial (view) <%= select('history', 'sel', history_list, {:selected => selected}, {:class => 'historyselect'}) %> <%= link_to_remote 'x',       :url => {:controller => 'rriki',                :action => 'clear_history'},       :html => {:title => 'Clear history'},       :method => :get %> <%= observe_field 'history_sel',     :url => {:controller => 'rriki',              :action => 'select_item_in_history'},     :with => 'history_sel' %> changing the select will call the action select_item_in_history with params['history_sel'] set to the selected value.

Partials can take parameters (called locals), but can crash your app if a caller does not pass a local and you try and access it in the partial. You can use the following construct to initialize a variable if it does not exist var = nil unless defined?var where var is your variable

When parts of a webpage are updated using AJAX calls (e.g remote functions) these updated parts do not show up when you ask Firefox for the webpage html (using CTRL+U). A hack to see the generated html from a suspect rails call is to simply print out the html on the webpage instead of executing it by doing: <%=h ...rails command... %> Instead of <%= ...rails command... %>

I had a select tag that I wanted to mess with a little to apply some styles etc. to. The select tag has an html_options hash and I was trying to use that. My initial attempt was select('history', 'sel', history_list, html_options => {:class => 'historyselect'}) WRONG This is not python, and even though the rails docs setout the syntax as: select(object, method, choices, options = {}, html_options = {}) ruby can not accept keyword arguments. Only positional, so you have to do: select('history', 'sel', history_list, {}, {:class => 'historyselect'}) The empty braces signify the empty 'options' argument, and the next set of braces signify the html_options hash

At NIH when you look at a grant they all have a Program Announcement number (PA). When you go to grants.gov they ask for the Funding Opportunity Announcement number (FOA). The first test of eligibility to apply for the grant is to realize that they both mean the same thing...

regular python shell: execfile('myscript.py') ipython: run myscript.py            : run -i myscript.py (if you want the script to have access to the workspace variables)

nose sympy

A tabular wiki page of GPLd or otherwise open source code that can be used to run neural network simulations. Notable among them is Brian , which is written in Python. The venerable NEURON also has hooks into python.

gattach was a handy tool to use for webmail clients like gmail. I couldn't find it anymore, but then from this discussion I found out that gattach is now affixa.

Firefox crashes semi-occasionally. On the plus side, when it recovers it repopulates any form fields I have been filling out. All is not lost...

The multi select does not work, unless you use user agent switcher to pretend you are IE6

white-space:nowrap;

object.class.to_s.tableize

Using subclipse: SVN exploring -> click on history -> right click on file -> copy

There are people, apparently, who use hex keys and whatnot to mess with the focus calibration of their nikon camera. I prefer to take pictures with mine.

Problem: Laptop (HP Pavillion DV2700) has an intermittent fan. Fan goes on for a second and then stops, goes on again, stops. While this may be OK for the hardware (but who knows) it drives the user nuts. Cause: Laptop bios upgraded to F.2E (latest) My Fix: Downloaded and installed F.25 (older version) and this stopped the intermittent fan. I hope that this does not lead to overheating problems, I should monitor CPU temps.

I'm talking about this lens . Its made in China, it costs about $130 now, bumped up from about $100 a year back. The focusing ring is dampened and easy to grip (Its a MF on the D40). The mount is metal, but not machined accurately - mine is a tight fit on the camera (and others have commented on this). The image quality is excellent. This is a set of images of a deck of playing cards shot at the nearest range and at different apertures. The images are 100% crops from center (left) to edge (right). The DOF at f/1.8 is really shallow. The cards look washed out at f/1.8, but if you look at the red diamond and the edge of the middle card, they are sharp, indicating that the DOF is shallow enough ( .1" or less ) that the card goes out of focus by the time you go from center to edge. At f/2.5 the sharpness and contrast are remarkable:

So here I was, sitting at a class in MIT and the instructor puts up a slide and there is a legend that says 'course coding'. It is clear from the concept that the meaning is 'coarse coding', with 'coarse' being the opposite of fine. I keep my big mouth shut, because we are here for the science, and I don't want to side track people pointing out pipifax things like typos on a slide. A few slides later we come across coarse coding, and it is again spelled 'course'. I keep quiet. Again, and again repeatedly on different slides. Now I know its not a typo. The instructor thinks that's the right spelling. I keep quiet. Some days later I come across the misspelling on some website. Then again on slashdot, and now I have to open my big mouth to relieve the pressure. Its 'coarse'. 'COARSE'. Meaning...well, not fine. 'course' means a path, like a race course, or the course of a river.

A month or so ago, my spouse got me something from Brookstone. It was a great idea, but I realized that the product did not work out for me. On the receipt there was a note saying that returns could be made up to 60 days. We went a month or so after purchase and were told that Brookstone's policy was to refund the money before 30 days were up and to give store credit after that. I personally think this is misleading. That store policy should be prominently displayed on the receipt where it says 60 days to return. Otherwise its a shady move - probably false advertising. A little bit on the range of mail in rebates - the whole idea with the mail in rebate is that a certain fraction of people will forget to mail it in, so you get more people to buy (they think they are paying less for it) but your actual revenues are more (because the average price is more than you say it is with rebate). Brookstone's policy is in the similar vein. A certain fraction of customers (like us) will se...

It just works. Not. Updated iTunes to 9, now it freezes, uses 100% CPU and locks up, randomly. Why do I mess with something that was working?

Q: Choosing a Personal Printer For the Long Haul (Writer is asking for advice on what printer to buy that will last him for ever and ever and cost nothing and will take direct hits from meteorites and keep working) A: The best laser printer is the one that uses the same toner cartridges as the one at work. (by Anonymous Coward on Thursday October 01, @10:38AM)

VisionEgg compiles and runs fine on Mac OS X using sudo python setup.py install, just make sure you have Pyro if you want to use the experiment server and GUI

Go to nexttag or some other site and figure out the price range of the product Go to several different resellers and check the prices. Do a search with the reseller's name along with the phrase 'bait and switch' Find the product on amazon, adorama, ritzcamera and keh.com If the Price of the product is much below (say 30%) the well know retailers' prices Accessories are correspondingly more costly Extended warranties are correspondingly more costly website sells the same product at a higher price and it looks like one is body only and the other is kit (but the website does not tell you) Then be wary. They could be Trying to bait and switch you (sell you another product after saying out of stock) Trying to sell you over priced accessories and warranties to make up Selling a used or refurb kit as new Just plain old scam you - take your money and not deliver the product.

A lens of a given focal length has a certain field of view. If you can focus the lens close enough, you can get large reproductions of objects. Such lenses are called macro lenses.

1:6.6 maximum reproduction ratio -> 10mm object will take up 1.515151515151 (sorry had to do that) mm on the sensor. DX sensor on D40 23.7mm -> 3008 pixels so 1.51 mm -> 192 pixels -> about 1in for a 200dpi print. So with the 50mm 1.8 AF-D lens if you shoot at the closest distance (about .5m) a 1cm object can be printed at 1in decently. Not that you would want to use this lens that way...

Like that used for indicating the evaluation of integrals between limits: \bigg| as in \frac{\rho}{4\pi}\left(-\frac{1}{r}\right)\bigg|_{r_{0}}^{\infty} from a hint here from robphy

Its billed as the world's fastest lens. A limited number were built for NASA (glamor portraits in outer space - astronauts photographed only by the light of their own instruments) and Stanley Kubrik snagged a few to make some obscure movie shot mostly by candle light (yep, he spent all his money on those fancy high speed lenses and couldn't afford real lighting). Here is a picture of one . And here is a page by the guy who modified the lenses for Kubrik. PS. You've probably figured out I was kidding about some of the stuff about astronaut portraits and Kubrik running out of money...

There are three dimensions to exposure: Aperture Shutter speed Sensitivity In film days adjusting sensitivity on the fly was not practical, so you basically had a two dimensional plane once you loaded film. The life of the camera computer was easy when you set the camera to A or S modes: all it had to do was adjust the free variable to maintain correct exposure. In M mode the camera merely informed you of exposure letting you roam freely in this 2D space. The D40 can be setup exactly this way if you select fixed ISO. If you select auto ISO, however, the camera now is handed two free parameters (for A and S) and one free parameter (for M). How does the D40 deal with this? For A mode the computer minimizes ISO and maximizes shutter speed. You can set a lower limit for Shutter speed and upper limit for ISO and the camera will drop shutter speed until it hits the lower limit and the start to bump ISO. For S mode the computer minimizes ISO. It will maximize the aperture until it reaches the...

(But couldn't find on google because it thought you were looking for compact flash memory cards) http://repairfaq.cis.upenn.edu/Misc/strbfaq.htm Hopefully you find this link if you are looking for Photographic flashes - AKA: Strobe Strobelight Flash Camera flash Compact flash (Hell why not)

I didn't buy this for my Film SLR because I cost too much. Currently Nikon's brand (ML-L3) costs $15 on Amazon/Adorama etc. and on Nikon Mall costs $20. However, if you look here (bestofferbuy) you can get an 'alternate version', called the YN ML-L3, for $4.80 and free shipping. I was a little wary at first and wondered if this was a scam, but I decided to try it out and ordered two (aha, see how this works, they price it less and that gets the sucker customer to buy more). I guessed it would take a long time to get here, but it took about a week and a half. I tried out the first one and it works fine. The unit comes with battery installed but with a plastic tab to keep it from discharging. These shady Chinese operators are moving upscale. (Actually it ships from Hong Kong. Don't know if that's any different anymore). I have plans for the other one. An intervalometer costs an insane amount of money. Say like $140. What I want to do is order a 555 and some pots f...

Any Nikon camera with lens info contacts (e.g. any DSLR and any newer Nikon) needs the BR2A reverser, rather than the BR2 to reverse lenses.

-moz-transform: rotate(-90deg);

CSS3 supports divs with rounded borders, but for now Firefox lets you use something like -moz-border-radius: 2em;

I needed to group records by year. From this post and the enumerate module docs we end up with entries = Entry.find :all, :order => 'date DESC' entries.group_by do |entry| entry.date.year end The group_by returns a hash with keys corresponding to the result of the block (i.e. the year)

So, how big a print can I make with a 6MP (3000x2000pixel) image, if I assume that the image is meant to be seen all at once? From wikipedia ( eye acuity ) we find that a human with 20/20 vision can resolve 2 arcminute per line pair. This means two pixels separated by 2/60 = .033 degrees they can be seen separately Then a 1000 pixels can subtend 1000/2 * .033 = 16.66 degrees, so a 6MP image can subtend 50x33 degrees. At a distance of .3m (arm's length) this works out to .358m x .195m (14.3"x7.8") At a distance of 1m this works out to 1.192m x .65m (47.5"x25.87") I don't think this is too shabby.

Set Fn button to control ISO Set AE/AF lock to AE only In A/S (Aperture/Shutter priority) modes Wheel alone controls Aperture(Shutter) Wheel + function controls ISO Wheel + (+/-) controls exposure compensation (I keep forgetting this) In M (Full manual) modes Wheel controls shutter Wheel + (+/-) controls aperture Wheel + function controls ISO Exposure is indicated on the bar graph In Auto mode you only get to control ISO

I'm sure Google crashes when you do this search. But here's what I think: The only way to get photographs you attach to is to take a lot of them as often as possible, look at the results and link it with what you did. Digital makes this process cheaper and faster. Digital gives you instant feedback. From the instant LCD display, to the home viewing on the big monitor to the prints at the dime store. More pictures, more fun. I think the guys who say 'all you need is a pinhole' are right. Really. It ain't the camera. I have photos I treasure from my Dad's Exakta RTL (with a busted exposure meter), from point and shoot Yashikas and Kyoceras, and from my Canon A510. From my D40 so far I have perhaps two photos I treasure for artistic reasons (out of may be 500). The camera and the lens just don't matter. Just take a lot of photos. And have fun. UPDATE: One thing though - the D40 has really good low light capability. I took several indoor shots with room lighting...

Photography increases my admiration for the human visual system. I look up into the night sky and I see the full moon, I see the stars around it and the houses below. Then I put my camera on a tripod and try to capture the same scene. WOW! The moon is BRIGHT! I mean you could shoot it hand-held (1/30th even at f13). But wait, at that exposure the stars are gone, not to mention the house. I go down to 1" at f13. Now I get the stars, not really the house and the moon is one big halo with no internal structure.

I got fascinated by the camera shutter mechanisms and started to do some reading: A great set of images of a shutter opening and closing . Read the tech details of how it was done. A very nice writeup with attractive hand drawn sketches of the principle of the focal plane shutter and some funny effects that occur with fast moving objects or flash use. I wanted to know more about the shutter mechanism. Nikon has two pages with tiny drawings [ 1 ],[ 2 ] A search on google images with the word "shutter mechanism" and filter by line art gives interesting results An example of how shutter speed knobs interact with the actual shutter is given here .

In 2006 I had taken a bunch of film photos and had them processed by shutterfly. Shutterfly also scanned these photos and put them in my account so I was happy. Finally this year I decided I wanted the scans on my computer and I ordered a DVD of them (you can't download the hi-res versions from the website). I was unpleasantly surprised when I got the scans back. They are 270 ppi or so, amounting to 1536x1024 from 35mm film. I would have expected something more detailed from them such as 2000 ppi or so. But it was a bad surprise as some of the photos were landscapes and I was looking forward to enlargements. I guess I'll have to dig out the negatives from the boxes.

Trigger sequence . Remote shutter release with great economy of components Shutter release with more components Big scale uP project with serial programming

Kingston SDGC 4GB class 6 (SD6/4GB) card. Auto focus (Prefocused by half shutter press before burst). Auto mode. Large/Fine Jpeg. Off white wall with a few objects on it. 23 pictures in 11 seconds. Buffer sat at around r4/r5 during burst. After burst the card activity light flickered for about 4s.

My own first SLR is the Nikon F65 which I got in 2001 for about $400 (more than my D40!). It was billed as an entry level SLR for beginners. That's me, a beginner for about a decade now. I've used a digital compact (Canon A510) since 2005 and details of the F65 slowly faded from my mind as it stayed stashed in the closet. But after I got the D40 I began to remember things - didn't it have a DOF preview, didn't it have this? That? So I got it out of the closet and lookee here, the F65 (Nikon entry level film) has: Depth of field preview Exposure bracketing Five (5) AF areas Pentaprism Top LCD It doesn't have two control wheels, but has the control wheel + modifier buttons. Hmm... methinks the Nikon engineers are losing to the Nikon marketing people (C'mon DOF preview, exposure bracketing, 5 AF areas these don't add to cost - they probably COST money to take away, the only reason to take these small things away is to make people buy the more expensive one isn...

I was reading an essay by a photographer who shoots 4x5 format for landscapes. Its very entertaining to read about how he focuses on a ground glass screen and then uses a loupe to check focus. But here's a sentence that I found entertaining because its technically wrong, but I think I know what he means: " Fourth, the inverted image on the ground glass creates a more direct visual impression because the brain does not have to flip the image upside down. This last remark is based on the fact that our eyes act as lenses and thus project an upside-down image of the world to the brain, which then has to flip it right side up. Because the ground glass image is inverted it is projected to the brain right side up thereby nullifying the need for the brain to rectify the image. " Its hard to explain why this is wrong but basically the brain is used to how it gets the images and it is harder for the brain to process an upside down image. Consider the empirical results that we fi...

I have a F65 which came with a 28-80mm lens. I used this lens on the D40. It required manual focus, the red focus dot did not work as a focus indicator and I could not select a focus area. (I had gotten the impression that the focus circuitry would still be working so that I could use the focus indicator to judge focus). The dot works. It just goes off when you are way off focus, flashes when you are close and is steady when you are focused. Now you know why my moon shot was out of focus and I was complaining that there was no red dot :P The exposure meter still gave readings, and they looked sensible. Here are two shots of the moon. One with the kit lens at 55m and the other with the manual lens at 80mm with a UV filter on it. The 80mm shot is blurry, either because of my poor focus, or because of a cloud infront of the moon. I'm going to try some more shots later at night. Kit lens at 55mm Film camera lens at 80mm This is the appropriate 1.5x magnification you expect from the di...

d40 wiki flikr d40 group

It was interesting that the D40 even beat out compact cameras from Nikon... The link to the live page is here .

I couldn't find a scientific answer to this one. Funnily enough I couldn't even find online how fast the D40 writes out its data. Perhaps its in the manual and I should just look. And what's with all these different speed metrics for SD cards !? Anyway, here's how I went about it. From yesterday's shoot I have 101 pictures totaling 204.6 MB (Large Fine Jpegs. I ain't no RAWer) = 2Mb/picture The D40 can shoot bursts of 2.5 frames a second = 5Mb/s. If we are to keep up with that we should have a card that is capable of at least 5Mb/s write speed. Thanks to wikipedia's page on SD cards , we learn that class 6 SDHC cards write at 6 MB/s and above and the 'x' notation e.g. 40x, 50x means 40x150kB/s. So we will need a class 6 card doing 5MB/s or more or a 33x card. Lets see how that works out for an amateur shooting like 10 pictures or so at a go.

In 2005 I bought a 512MB SD card for $37. Now, in 2009, from the same company you can get a 4GB SD card for $9.

from matplotlib.ticker import NullLocator pylab.gca().xaxis.set_minor_locator(NullLocator())

pylab.xscale('log')

pylab.xticks(rotation=45) From the api .

You need to watchout for depth of field at 55mm. I have to reprogram myself after 4 years of using a compact. I keep thinking f5.6 is 'Ok for things at inifinity, like that building over there' But it ain't. You have to do tricks like 'hyper focus', i.e. focus at infinity (like a building behind this one) and then recompose, or stop down the lens more. Lets actually work this out: Circle of confusion ( Zeiss formula ) c = d/1730 where d = sqrt(23.7^2 + 15.6^2) = 28.37mm c = 0.0164mm Hyper focal distance ( Wikipedia ) H = f^2/Nc For the shot I had f = 55mm N = 5.6 H = 32937.71 mm = 32 m The building was probably 10-15m away, and I focused on that, reducing my DOF. I should have kept my aperture at around N = f^2/Hc = 55^2/(15000*.0164) = f12 for a good shot. Alternatively, I should have focused on the farthest part of the building, locked focus and recomposed. Stop down the lens Kaushik, stop it down. This 'ere's a REAL camera :)

Metered on the sun reflection on the water and recomposed Metered on the cobblestones and recomposed

The D40 is a great camera. It has spot metering , exposure lock and focus lock . These are important things for me because I like to play with pictures taken against light, which are challenging even for film. It's evaluative metering is superb, which is for everything else. I have no problems with the controls, though some people say they are cumbersome. At most, you have to hold down a modifier button while spinning the thumb wheel. The exposure lock button is the only inconvenient thing - you have to jam your thumb next to your eye as you look through the viewfinder. I haven't made prints yet. Theoretically 6 MP will yield 10"x 6.6" prints at 300dpi and 20"x 13" at 150dpi. We'll see how that turns out. The D40 is as light as my film F65 and lighter than the fancier older film Nikons. It feels solid in the hand, more solid than the F65. The kit lens (18-55 Nikkor G) is great, its quiet and has great depth of field. Be aware that you need to stop down ...

Having shot almost exclusively with a compact digital ( Canon A510 ) for the last four years I forgot how much fun and challenging optics is. The small sensor and the short focal length of the compact, much like older, rangefinder point and shoots (e.g. yashika mg-1 ) gave almost pinhole camera like behavior. Basically with these cameras infinity was about an arms length or so away and I would be more causal with the focus. With the D40 its back to the F65 habits. Depth of field is back down (which is what I wanted). But I'm not used to it any more. For this shot (click for full size crop) I thought "I'll just focus on them clouds there, the trees are at infinity, just like the clouds, it'll be all right". Not so. The trees look annoying because they are slightly out of focus, but you can see the sharp edge of the cloud. f6.3, 18mm. Shoulda stopped down the lens more. In case there was any doubt, the kit lens can focus: So I have no one to blame but myself...

The D40 has no DOF preview button. But, does a digital camera really need one? If you have time to stop down the aperture you have to to shoot an image, look at it in the LCD and decide - do I open up or close down the aperture more?

Peter Jackson should sell his copy of slumdog millionaire and buy himself a decent tripod.

This website has a nice writeup.

Original Color and saturation adjusted a bit A sunset? No. Actually, this is not a sunset. Its a city rise. The red glow is from Revere, or one of those other cities to the east. This shot was taken facing east. In short: The D40 can do sunset exposures just fine (These were all shot with aperture priority). Some shots were with -1 EV compensation. The autofocus will work as long as there is even a tiny bit of light and the subject has contrast. I used the tree to focus, and this was nice and contrasty against the sky.

I got the Tiffen 52mm UV (Haze) filter and the Matin heavy duty LCD protector from the same company I bought the camera from. The LCD protector is one step up from the films you could get for your PDA. This is a thin sheet of polycarbonate that sticks to your LCD. I misaligned it at first and had to pull it off, and it came off without leaving any residue. It sticks quite well but is very reflective. In bright light I have a feeling it might reduce the contrast of the LCD. I plan to leave the protector on until it gets very scuffed, and then replace it leaving the original LCD scratch free (hopefully). The Tiffen filter is cheap, its not multi-coated, so you can expect a little glare when you have a bright light source. An example is shown below: The reflection is due to the UV filter. The only other thing I want to get is a 4GB card. My 1GB card will store about 270 Fine JPEGs, probably half the amount of RAW.

Yes, you can get them for the D40. There's a very pricey one from Katz Eye . It runs into $100 to $155. It has some good reviews . There is a pretty cheap one you can get on ebay right now ($34 with shipping), and it might be the same you get from focusingscreen.com ( This one costs $40). A video tutorial for replacing the focusing screen: But I would use rubber tipped tweezers, rather than straight metal ones. And don't film your self doing it... :) The google search url .

I am pretty pleased with high exposure times on the D40. The last time I really played with long exposure was with my film camera. What I am NOT pleased with is MY inability to focus properly - aargh! But in my defense there isn't a focusing screen (like split prism, or ground glass). I wonder if I can get one of those for the D40? Click on the examples to get a 1200px downsampled versions. If you ignore my amateur focus you will note the amazing lack of noise even on 30s long exposures. I like this sensor. In the last two pictures below I let the D40 decide the exposure and used aperture priority. The D40, like the F65, knows exposure. (For normal photos, on the F65, I ended up deciding to let the camera decide it. Whenever I took over I did something wrong. Only for special shots - like the really long exposures - did I put everything on manual. I think the same is going to be true of the D40.) Its amusing though, these last two shots have the same exposure, but they are lit dif...

Picture (click to get a downsampled 1280px image). This was taken at sunset with 800 ISO setting with kit lens at 18mm zoom, no VR, handheld. The overall impression is good, but is marred by the combination of hand shake and higher ISO that gives the photo a softness that hurts the edginess of the main subject. The auto focus was perhaps also not the best. The following full size segments of the original image illustrate this point:

ISO 200 ISO 400 ISO 800 ISO 1600 ISO 3200

Obtained this as refurbished from Adorama for $375 with 18-55mm DX AF-S lens. Adorama shipped it for free and it arrived overnight (NY to MA). Its declared as refurbished but the body is blemish free. I would say this is a new camera (unless some one soaked the interior in dust/water/acid etc). There is a 90 warranty from Nikon on both lens and body. From the exif information on the pictures I see that the camera has about 2600 shutter actuations, and the serial number has two dots punched in at the start and end. According to this page those dots indicate Nikon has refurbished the camera. I found a few dust specks on the viewfinder. (Aiming at the sky and looking around the field of view). I remember on the old Nikons, that my uncle had, you could pop-off the pentaprism and clean it all out, but I don't think you can do that here. The camera with this lens weighs about as much as my Nikon F65 (or N65), which is to say, less than a kilo. The battery needs to be charged, but it h...

I know firefox is so unhip now, with that chrome or plating or whatever they call it browser. But really, being able to drag a tab from one window to another? Nice.

It wasn't always clear from reading up on websites and forums what exactly are the differences between consumer DSLRs and pro DSLRs. I'm making a short generic list here of what Nikon pro cameras may have that consumer one's don't (listed according to how important they were to me) Aperture stop down to preview depth of field Fast mechanical shutter (rather than a combination of slow mechanical shutter and sensor gating which can lead to streaking in extreme situations ) Exposure bracketing (shoot three or more shots in quick succession with slightly different exposure levels) 1/3 EV steps for ISO rating (i.e. pro cameras can do ISOs inbetween 100 and 200) Motor for AF lens in body (If you have many old lenses this counts as a cost savings) Metal body that can withstand physical shocks better Dust removal on the sensor More auto focus points Top panel LCD for settings summary Basically, a "pro camera" is designed to withstand being dropped and bumped (you'...

. -> class selector # -> id selector so .bregma { width:10cm; } -> <div class="bregma"> #lambda {widh: 5cm;} -> <div id="lambda"> PS. The # symbol is called an octothorpe (Thanks to Vicki for catching the spelling mistake)

The hard working folks at matplotlib have put out a new release candidate with interesting new features. Remember - its a release candidate. Not (yet) for production. Get it from http://drop.io/xortel1# Install using sudo easy_install ~/Downloads/matplotlib-0.99.0.rc1_r0-py2.5-macosx-10.5-i386.egg On mac you will hear complaints about Searching for matplotlib==0.99.0.rc1-r0 Reading http://pypi.python.org/simple/matplotlib/ Reading http://matplotlib.sourceforge.net Reading https://sourceforge.net/project/showfiles.php?group_id=80706&package_id=278194 Reading https://sourceforge.net/project/showfiles.php?group_id=80706&package_id=82474 Reading http://sourceforge.net/project/showfiles.php?group_id=80706&package_id=82474 Reading http://sourceforge.net/project/showfiles.php?group_id=80706 No local packages or download links found for matplotlib==0.99.0.rc1-r0 error: Could not find suitable distribution for Requirement.parse('matplotlib==0.99.0.rc1-r0') but it will be ins...

From here class A def self. class_method puts 'class method' end def instance_method puts 'instance method' end end

http://homepage.mac.com/thomasw/OpenTerminal/ Lets you select a folder in finder and opens a terminal cd'd to that folder. Interestingly, this is a free but not opensource app. This seems to be the culture around Macs - apps written specifically for Mac are less likely to be opensourced. Thanks to Jon Hendry for the link.

What. A. Pain. UPDATE: I'm now using thin instead of mongrel. When you go to do sudo gem install mongrel it will barf with some errors related to a file called http1.c Stop. Do not adjust the channel. There is nothing wrong with your computer. Somebody goofed in the source code. From instructions here , you have to make the following changes to the source. Remember to edit as root, don't run gem install mongrel again - you will overwrite your corrections. This stuff was worked out by Alan and clarified by Ami Mahloof 1) cd /usr/local/lib/ruby/gems/1.9.1/gems/mongrel-1.1.5/ext/http11 2) sudo vi / mate on http11.c and: replace line 77 with for(ch = RSTRING_PTR(f), end = ch + RSTRING_LEN(f); ch < end; ch++) { replace line 172 with colon = strchr(RSTRING_PTR(temp), ':'); replace line 174 with rb_hash_aset(req, global_server_name, rb_str_substr(temp, 0, colon - RSTRING_PTR(temp))); replce line 176,177 rb_str_substr(temp, colon - RSTRING_PTR(temp)+1, RSTRI...

Invoke with python -h this prevents print statements from being buffered (e.g. when being dumped into a nohup.out file)

Use the listings package , in combination with the colors package Use \usepackage[usenames]{color} to preload 68 color definitions (otherwise you only get about 5 boring colors). Documentation for colors is here .

Hmm... I guess they throttle downloads, but I have 5/20 service, how can I upload faster? This is the speed test without secure conection

import socket socket.gethostname() From a hint here .

If x is multidimensional pylab array x.argmax() returns the flat index (converts the multidimensional array into a flat vector before finding the max/min). The pylab function unravel_index comes to our help pylab.unravel_index(x.argmax(), x.shape) From a hint here .

Remember to destroy job servers after they are done. My nice animation generator crashed sometime over the weekend with the following death rattle: Traceback (most recent call last): File "animate_array_job.py", line 168, in tscale = tscale, dpi = dpi) File "animate_array_job.py", line 92, in process_file job_server = pp.Server(ppservers=ppservers) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/pp.py", line 336, in __init__ self.set_ncpus(ncpus) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/pp.py", line 494, in set_ncpus range(ncpus - len(self.__workers))]) File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/pp.py", line 141, in __init__ self.start() File "/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/pp.py", line 148, in start shell=True) File "/L...

If the jobs are too short they may not get submitted to the remote machine and may all execute on local. pp submits jobs to remote machines only after running out of workers on local File handles are opened on the remote machines. You can't pass a file handle as a function argument TypeError: can't pickle file objects

Among the many libraries for parallel processing in python I chose what seemed to have one of the simpler interfaces - Parallel Python . There is one trick that is not apparent from the docs: The function you call has to be 'self sufficient'. You basically have to write up the function you call as if it were a script. So the function has to have the imports etc within itself. This is not a biggie, but it gets confusing until you figure it out. Original code: # module x ----------------- import a import b def f1(g): f2 f3 def f2(): def f3(): # Calling script import x x.f1(2) x.f1(4) x.f1(6) x.f1(8) Parallelized code # module px ------------------------------ def pf(g) import x x.f(g) # New calling script import pp import px ppservers = () job_server = pp.Server(ppservers=ppservers) jobs = [] jobs.append(job_server.submit(px.pf, (2,)) jobs.append(job_server.submit(px.pf, (4,)) jobs.append(job_server.submit(px.pf, (6,)) jobs.append(job_server.submit(px.pf, (8,))

ls | wc -l

ax.yaxis.tick_right() Note that is you change tick properties before this (e.g. change size of labels etc.) that will be all reset

Use raise StopIteration : try: for loop: for loop: for loop: if condition: raise StopIteration() except StopIteration pass

With interactive backend (eg Tk) f = pylab.figure(figsize = (7,10)) f.get_size_inches() -> array([ 7.175, 10.175]) The saved pdf is also of this size. It becomes extreme with smaller figures: f = pylab.figure(figsize = (1,1)) f.get_size_inches() -> array([ 3.275, 1.175]) This last I can see as a function of getting the tool bar to fit. With Agg the saved figure is the size you ask for

Reading a paper about neural circuitry. Came across the word 'resonant circuitry'. Looked it up on wikipedia . Knew it had to do with band pass circuitry. Looked that up on wikipedia . Read in that entry that Thomas Pynchon claimed the character Kilroy was based on the circuit diagram for a band pass filter. You be the judge. Any hoo, went to Pynchon's page on wikipedia and started to read. On the entry for his novel V , read about yoyodyne corp. Hey I know that from the GPL. Went to the (fictional) webpage for yoyodyne cor p ... Wait. Whaa!? What's all thsi? What's the time? Where am I? What am I doing here? Wasn't I just reading a paper on neural circuitry?

So I voted as follows: KeePass Password Safe for Best Project (I would have liked matplotlib in the list) eViacam for Best New Project matplotlib for Best Project for Academia Audacity for Best Project for Multimedia (mencoder, if it was on sf, would have won mine) OpenOffice.org for Best Project for Government KeePass Password Safe for Most Likely to Change the Way You Do Everything (I would have liked matplotlib in the list) I would have liked to see Matplotlib in the categories ' Best Project' and ' Most Likely to Change the Way You Do Everything' too, but KeePass is a good choice. I didn't vote in a category when I didn't know any of the choices. eViacam is a mistake. I tried to get rid of it but couldn't cancel that vote. I picked it at first even though I knew nothing about it because I thought it was a good idea for a project, but later decided it wasn't right to vote on a project I haven't used.

nohup command 2>file1.txt 1>file2.tex & or nohup command 2>/dev/null 1>/dev/null

Put import pdb; pdb.set_trace() Where you want the code to stop. Once in debugging mode type 'r' to return from trace and be where you stopped the program. From a tip here .

Use the highest protocol you have available - which will usually be binary. So as example: import cPickle import pylab z = pylab.random((10,10)) z ndarray 10x10: 100 elems, type `float64`, 800 bytes len(cPickle.dumps(z)) -> 2371 len(cPickle.dumps(z, cPickle.HIGHEST_PROTOCOL)) -> 934 z = pylab.random((50,50)) z ndarray 50x50: 2500 elems, type `float64`, 20000 bytes len(cPickle.dumps(z)) -> 55586 len(cPickle.dumps(z, cPickle.HIGHEST_PROTOCOL)) -> 20134 For some reason, I thought the default was to use the most efficient protocol, but it isn't. cPickle.dump? Type: builtin_function_or_method Base Class: String Form: Namespace: Interactive Docstring: dump(obj, file, protocol=0) -- Write an object in pickle format to the given file. See the Pickler docstring for the meaning of optional argument proto. Hence my slow processing and bloated data files... Note that load figures out the protocol automatically...

The os module has functions ( os.rmdir, os.removedirs ) that can remove empty directories but they will not mess with non-empty ones. The shutil module has a function ( rmtree ) that will do this (From this thread in the python mailing list).

One of the frustrating things about matplotlib is its lack of 3D plotting. If matplotlib were a mediocre library it wouldn' hurt. But it is a GREAT library and produces really good looking plots. So the lack of 3D plotting sometimes makes me want to go out and strangle somebody. There has however always been a furtive 3D plotting feature in matplotlib, and apparently , its being worked on some more. Yeehah! No more futzing with pyVtk. Important links: Docs for 3D features Installing the svn code (that has all this goodness)

Drop down the 'mailing lists' tab. There is a search option there.

Use the pylab.Circle command import pylab #Imports matplotlib and a host of other useful modules cir1 = pylab.Circle((0,0), radius=0.75, fc='y') #Creates a patch that looks like a circle (fc= face color) cir2 = pylab.Circle((.5,.5), radius=0.25, alpha =.2, fc='b') #Repeat (alpha=.2 means make it very translucent) ax = pylab.axes(aspect=1) #Creates empty axes (aspect=1 means scale things so that circles look like circles) ax.add_patch(cir1) #Grab the current axes, add the patch to it ax.add_patch(cir2) #Repeat pylab.show()

I dislike the indistinct icons in the cookie manager plugin CSlite. In Firefox/extensions/{00084897-021a-4361-8423-083407a033e0}/ (the directory for this particular extension) we find chrome/cookiesafe.jar From a hint in a thread here , we learn that the .jar file is just a .zip file, and we can extract that to find skin/classic/cookiesafe and a whole bunch of .gifs there. We can then change those gifs and change the icons that are used in the application.

I was using the Permit Cookies extension for firefox, but it hasn't been updated for a few cycles of firefox updates. It works fine, but I started to look for something else. I found CS lite which has a more convenient interface (a popup menu from the status bar). The only gripe I have so far is that the icons in the status bar are not very clean.

Downloaded and started playing the Crysis demo. On my integrated graphics MoBo, naturally I had to set everything down to low, but even then it can get choppy when in the jungle. And the graphics look so crappy I think - hmm, maybe I'll just play Far Cry. Tom's hardware has a great page where you can compare the performance of various cards with various games at various settings when searching for a cheap graphics card for crysis.

And make it all mysterious and make me think like my computer has hung, until I figure out that its just the track pad.... grrrrr.... And it reset my keyboard repeat rate too...

In matplotlib, the way to change axes tick label sizes is to do: for label in ax.get_xticklabels() + ax.get_yticklabels(): label.set_fontsize(12) From matplotlib-users

From other parts

Use the Format** functions as illustrated in the major-minor demo. e.g. pylab.plot([0,1,2],[0,1,2]) major_formatter = pylab.FormatStrFormatter('%2.1f') pylab.gca().xaxis.set_major_formatter(major_formatter) pylab.gca().yaxis.set_major_formatter(major_formatter)

ftp ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p129.tar.gz tar -xvf ruby-1.9.1-p129.tar.gz cd ruby-1.9.1-p129 ./configure --enable-shared --enable-pthread CFLAGS=-D_XOPEN_SOURCE=1 make -j4 sudo make install Installs in /usr/local/bin, make sure to point path there

Finally, some useful information on Slashdot. I knew all those hours invested in reading inane comments riveting articles would pay off. HP is recalling batteries. The list is here

Mistaken Identifiers: Gene name errors can be introduced inadvertently when using Excel in bioinformatics If you are too lazy to get to the punchline: "MatchMiner [1] and GoMiner [2] are two bioinformatics program packages we published recently in another Biomed Central Journal, Genome Biology. When we were beta-testing those programs on microarray data, a frustrating problem occurred repeatedly: Some gene names kept bouncing back as "unknown." A little detective work revealed the reason: Use of one of the research community's most valuable and extensively applied tools for manipulation of genomic data can introduce erroneous names. A default date conversion feature in Excel (Microsoft Corp., Redmond, WA) was altering gene names that it considered to look like dates. For example, the tumor suppressor DEC1 [Deleted in Esophageal Cancer 1] [3] was being converted to '1-DEC.' Figure 1 lists 30 gene names that suffer an analogous fate."

My choices: - Matplotlib - Inkscape

A search on google for pylab append to array brings up a page full of Matlab hits. Why, I wonder?

My MATLAB origins betrayed me. I kept thinking - you can't put function definitions in a script in Python. Man, I gotta write a module and THEN a script that calls the module? But, in Python, you can include function defs in a 'script'. So the following works perfectly well: def func1(): print '1' def func2(): print '2' func1() Take that MATLAB.

window->freeze panes : keep cells to the left and top (inclusive) of selected cell frozen as you scroll

Todays xkcd made me laugh. A small pause in the downhill journey of that site.

http://sarien.net/

is not very good. Its kind of crowded and ungainly. Don't you think they should have come up with something more visually appealing? To me, even plain type looks better! Like this GPL v3

I first ran into the GPL in some book. It could have been a coding book or a latex book. I didn't care about licenses at that age, but I remembered it because it contained the following extract: You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. signature of Ty Coon , 1 April 1989 Ty Coon, President of Vice Now, these guys must be fun to hang out with! That's what I thought. Recently, I looked up GPL3. Stallman's blurb on why we should switch was all peachy and militant. But what really disappointed me was the end of the license: If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode: Copyright (C) This progra...

Ahh Ruby... Suppose you have a string class that corresponds to a class name and you want to call a certain method on it, what do you do? Well you could do eval class + '.method' but that will be slow (as evals are slow) and apparently that looks ugly. But the creator of Ruby must have run into that issue often. Because what you can do, is class.constantize.method This is an inflector that tries to find a declared constant with the name in the string. And in Ruby classes are constants ...

Rubular

to put on your website is found under ProjectAdmin->Analytics

sudo gem install bluecloth in application_helper.rb do require 'BlueCloth' Invoke by calling markdown(text)

Contents of module.py def haha(): print 'haha' def mama(): print 'mama' if __name__ == "__main__": haha() Now invoke module.py as a script python module.py output: haha

I think the IRS did a good job on the free file interface. The interface works on Firefox3.0 on a mac. I'm assuming it works on windows. There are a few minor glitches with cursor positioning on some text fields (when you need to go back and delete/edit stuff in a field) but its an allround good job. If all government stuff was like this it wouldn't hurt so much to pay the taxes.

I'm working on a new rails application. In one of the tables I have a field called 'type'. Everything was going fine, but whenever I set the 'type' field and saved the record it ignored the contents and set it to NULL. I couldn't figure it out. Tangentially, I had set a bunch of fields to be 'string' and these are translated to be varchar(255) in the sqlite database and I wanted to test what happened if I went over the 255 character limit. So I typed in a string 260 characters long into the 'type' field using an external database app and saved the record. It saved just fine, and kept all the characters. Now I thought, let me load this in my rails app and see if it still sets it to NULL. I loaded it and got back this error message: ActiveRecord::SubclassNotFound in ItemsController#show The single-table inheritance mechanism failed to locate the subclass: 'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk...