Wikipedia:Reference desk/Archives/Computing/2012 November 14

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November 14

Changes in emacs to a C file are ignored when tested in the terminal

I've hit a snag while attempting to work on a lab for school, and I can't understand what I am doing wrong. This lab involves producing ASCII art out of sterisks, specifically making a "T" out of stars. My problem doesn't even let me edit my work, it ignores any changes I've made since I saved my first draft of the starT.c file.

I am repeatedly editing starT.c in emacs, yet when I ./starT it does not reflect my changes, though I am doing ctrl-x ctrl-s after every change. I can verify this because I typed gibberish code into the program but it did not affect it in any way.

So, my steps are:

1) reach /cs/student/myname/cs16/lab03

2) type "emacs starT.c &"

3) edit the code and ctrl-x ctrl-s

4) in terminal type "./starT 3 3" (I've been using 3 by 3 for my default test)

5) It ignores any changes I made in step 3.

Do you know why? 128.111.43.43 (talk) 02:35, 14 November 2012 (UTC)

In Emacs do M-x compile and for the compile command do

gcc starT.c && ./starT 3 3

Hcobb (talk) 03:03, 14 November 2012 (UTC)

Hcobb is right. Your starT.c file is a plain text source file, and you need to compile it to obtain an executable file which will finally print out your art. (Please look at articles I've linked in the sentence above.) --CiaPan (talk) 06:32, 14 November 2012 (UTC)

Compile and link, that is. Hopefully the above command will do both. StuRat (talk) 07:38, 14 November 2012 (UTC)

You'll need to do

gcc starT.c -o starT

to create an executable named "StarT", you'll probably end up with "a.out" if you just do "gcc starT.c". Hopefully, since you seem to have an executable that you have made at least once, we'll have refreshed your memory enough on what you did to compile it the first time. 209.131.76.183 (talk) 13:28, 14 November 2012 (UTC)

Would a killer whale in the clouds have saved Romney?

Has any Cloud computing vendor written up how their services would have kept ORCA (computer system) from beaching? Hcobb (talk) 03:05, 14 November 2012 (UTC)

Not as far as I know. Cloud hosting might have solved the server capacity / bandwidth issues, but from what I've read the problems with ORCA went far beyond that. The people responsible sent out the wrong passwords, forgot to redirect www.whatever.com/orca to https://www.whatever.com/orca, didn't tell volunteers that they needed to pick up certain documents, only sent instructions the night before the election, performed no live testing etc etc. "If you used our services, the project would only have been a big disaster rather than a huge disaster" isn't a particularly compelling ad. 59.108.42.46 (talk) 03:55, 14 November 2012 (UTC)

The oddest part to me is that the American nominating process should have been the perfect test ground to build up and test such a system. First test it in the straw polls, then use it for the first few small states, building up to Super Tuesday, etc. So what was Romney using for tracking during the primaries? Hcobb (talk) 04:48, 14 November 2012 (UTC)

It didn't matter. Romney never won a primary with multiple contenders. For a mathematical analysis of his candidacy see Safe + Moderate ≠ Electable, Low-beta isn’t always better. μηδείς (talk) 05:24, 14 November 2012 (UTC)

For a party that supposedly stands for business their marketing skills and control of their systems just sucked. As to having a high beta candidate if that meant a Tea Party one then the demographics are against such a person winning. It would have reduced the mean and I'm not at all certain it would have increased the standard deviation anywhere near enough to compensate. Dmcq (talk) 12:12, 15 November 2012 (UTC)

One of the main problems with ORCA was that it was thrown together far too quickly. The Arstechnica writeup makes it sound like they were editing the documentation up until two nights before the election. Nobody, not even a really accomplished software company, can make something like that work in that small of a time window. The whole project was marked by a clear lack of appreciation of the real-world technical difficulties of such a thing. But it doesn't seem like it would have affected the overall election too much anyway. Even if, by some miracle, Romney had gotten enough extra turnout to win Florida, Virginia, and Ohio — the closest states — Obama still would have had over 270 electoral votes in far less competitive states. You'd have to imagine ORCA delivering all three of those plus Colorado for it to have tipped it — an extra 5% pro-Romney turnout. That's a lot to ask for from a piece of software. --Mr.98 (talk) 16:54, 15 November 2012 (UTC)

More broadly, what will IT do for campaigning in the future? Are we going to see a unified smart phone social media app that brings all volunteers for all candidates of a given party together and then has a two-way link to each campaign office? Hcobb (talk) 16:48, 14 November 2012 (UTC)

Take a read of the RD header. Nil Einne (talk) 02:13, 15 November 2012 (UTC)

randomly changing fractal wallpaper

How can I get wallpaper that is a dynamically changing fractal composition that doesn't just repeat a loop? I use an NV78 Gateway running Windows 7. Thanks for any and all close answers. μηδείς (talk) 07:16, 14 November 2012 (UTC)

Do you want it to randomly pick from a large group of fractals, or actually generate it's own, by varying parameters randomly ? StuRat (talk) 07:35, 14 November 2012 (UTC)

I'd like one fractal that would slowly evolve but not in a loop, which is why I said "random". An occasional change of underlying form would be okay, but I want the moment-to moment evolution to be organic, not just a bunch os flashes from randomly collected still to random still. Basically, I want a programy like those of basic screen saversm bu for my desktop. μηδείς (talk) 07:46, 14 November 2012 (UTC)

Is this what you had in mind (only fancier, with color and shading): [1], [2] ? Here's a screensaver that does leaf forms: [3] (do a find on "Paprotka"). StuRat (talk) 09:14, 14 November 2012 (UTC)

Use Winamp visualizations (AVS or Milkdrop) in desktop mode. Try googling the words "winamp fractal visualization". Activating desktop mode for MilkDrop: Preferences (Ctrl-P) > Plug-ins > Visualization > Select "MilkDrop vx.xx". Click on configure and select Render mode: "Desktop Mode (using overlays)". Trio The Punch (talk) 12:16, 14 November 2012 (UTC) p.s. Watch this if you want to use a fractal screensaver on your desktop.

Was more looking for what Trio has linked to, Stu. But thanks because you have reminded me of the fractal lifeforms from Richard Dawkin's book--I'll have to look for those and see if I can get the program off the internet. As for Trio's links, I will have to mess around for a while, so I'll get back if I need help or when I succeed. Thanks. μηδείς (talk) 17:33, 14 November 2012 (UTC)