Search found 221 matches

by kmatzen
Sat Jul 17, 2010 3:56 am UTC
Forum: Computer Science
Topic: IF-THEN operations
Replies: 8
Views: 1652

Re: IF-THEN operations

I'm designing a very simple computer, essentially for fun. But then, one thing I can't figure out is how IF THEN operations are processed in the ALU. Say I want to compute: "IF the number at register XXXXX is bigger than the one at YYYYY, THEN..." and I load them to the ALU's accumulator ...
by kmatzen
Fri Jul 16, 2010 7:49 pm UTC
Forum: Computer Science
Topic: IF-THEN operations
Replies: 8
Views: 1652

Re: IF-THEN operations

Er, I accidentally assumed you would be using two's compliment signed comparison which might not be the case. If you are doing unsigned comparison, then this won't work. Therefore, for unsigned comparison, you could check the carry out bit from the ALU. This might make the critical path of your circ...
by kmatzen
Fri Jul 16, 2010 4:33 am UTC
Forum: Computer Science
Topic: IF-THEN operations
Replies: 8
Views: 1652

Re: IF-THEN operations

Compare operations are usually just subtractions that only set the condition flags, instead of writing the result to a register. Kind of. You don't need to do a complete subtraction, you just need to compare bits from the msb down until you get a mismatch, so on average a comparison operation can b...
by kmatzen
Tue Jul 13, 2010 4:54 pm UTC
Forum: Coding
Topic: coworker rants
Replies: 92
Views: 14603

Re: coworker rants

he was using the data from three accelerometers (x,y,x) to position the device in a virtual space That does sound dumb for masters level work. Dead reckoning doesn't really work for this sort of thing, especially if he's using cheap MEMS sensors to do the job. Maybe he had built a map of wifi signa...
by kmatzen
Mon Jul 12, 2010 4:19 pm UTC
Forum: Coding
Topic: coworker rants
Replies: 92
Views: 14603

Re: coworker rants

psykx wrote:He was trying to do something doing triangulation from accelerometers on mobile devices (G1).


I don't even know what it means to perform triangulation using accelerometers.
by kmatzen
Sat Jul 10, 2010 5:16 pm UTC
Forum: Computer Science
Topic: I have an interesting question...
Replies: 13
Views: 2532

Re: I have an interesting question...

thejman129 wrote:Say you programed a super computer to randomly produce either a <0>, or a <1>. Because of the simplicity of generating a binary digit, would the computer not have the power to run at an extremely high rate?


Generating a random binary digit is not exactly simple.
by kmatzen
Fri Jul 09, 2010 8:09 pm UTC
Forum: Coding
Topic: coworker rants
Replies: 92
Views: 14603

Re: coworker rants

I once had to explain to a student studying his masters in CS that he didn't need to implement error correction because he already used TCP streams. facepalm facepalm facepalm Was the masters in computer systems? If it was theory then knowing that may not have been of much use. Was the student's re...
by kmatzen
Wed Jul 07, 2010 7:57 pm UTC
Forum: Computer Science
Topic: Career change to CS
Replies: 13
Views: 3124

Re: Career change to CS

rg43, I just thought of something. Do you have a school nearby that offers a degree in Management Information Systems? I know someone from U of Minnesota that got a bachelors in MIS and is now a software dev at Thomson Reuters. I've gotten the impression that it's a more business focused track than ...
by kmatzen
Wed Jul 07, 2010 1:20 am UTC
Forum: Computer Science
Topic: Career change to CS
Replies: 13
Views: 3124

Re: Career change to CS

TopCoder has a lot of good practice algorithmic challenges. My speed programming class used http://www.amazon.com/Programming-Challenges-Steven-S-Skiena/dp/0387001638/ref=sr_1_1?ie=UTF8&s=books&qid=1278466750&sr=8-1-catcorr These may not directly address the job interview needs, but perf...
by kmatzen
Tue Jul 06, 2010 6:45 pm UTC
Forum: Computer Science
Topic: Career change to CS
Replies: 13
Views: 3124

Re: Career change to CS

If you have a compelling statement of purpose then you might have the chance to get into a graduate program. I've heard of people in my program going for CS Ph.D.s after doing different bachelors. Some examples include mathematics, economics, natural sciences, etc. If all you want to do is programmi...
by kmatzen
Sat Jul 03, 2010 3:48 pm UTC
Forum: Computer Science
Topic: About solving deadlocks
Replies: 2
Views: 1554

Re: About solving deadlocks

I think creating a hierarchy is a pretty common solution. If you draw out the dependency graph for the mutexes, then it's easy to prove that, because the graph is a tree, no dependency cycles can form and deadlock is impossible.
by kmatzen
Fri Jun 25, 2010 5:58 pm UTC
Forum: The Help Desk
Topic: Program to combine keys
Replies: 9
Views: 1673

Re: Program to combine keys

If it was written in VB or C#, then you could use .NET Reflector to easily decompile it. You said this was for a banking software company. I probably wouldn't want to purchase software from your company if their employees have to ask how to do something like this on an xkcd forum. This seems sketchy...
by kmatzen
Sat Jun 19, 2010 2:18 am UTC
Forum: Coding
Topic: MATLAB noob coder needs help with textscan
Replies: 2
Views: 3246

Re: MATLAB noob coder needs help with textscan

I'm not sure if this is exactly what you need or want, but here's how I fixed it up. fid = fopen('pontos_palavra.nmea'); cell_palavra = textscan(fid, ['%*s %u %c %f %c %f %c %f %f %u %f ' ... '*%2c\r\n %*s %u %f %c %f %c %u %u %f %f %c %f %c %u *%2c\r\n ' ... '%*s %c %u %u %u %u %u %u %u %u %u %u %u...
by kmatzen
Mon May 31, 2010 7:34 am UTC
Forum: Coding
Topic: What did YOU major in?
Replies: 4
Views: 1078

Re: What did YOU major in?

Coffee Stain, based on your post and location, are you starting at Microsoft? If so what team? I was there for an internship last summer with Windows Azure. I wonder if I remember you. As far as the 4 year thing is concerned, it might be better to at least get a masters while you are at it, especial...
by kmatzen
Sun May 30, 2010 7:48 pm UTC
Forum: Computer Science
Topic: Cryptograhy.
Replies: 7
Views: 2586

Re: Cryptograhy.

> 1.what is the best online free server that i can found from online that can be store my patient's information? > 2.what algorithm of cryptography is recommended to use.not difficult but safety algorithm. I don't really understand what the project is. Are you just going to throw a bunch of entries ...
by kmatzen
Sun May 30, 2010 7:28 pm UTC
Forum: Coding
Topic: What did YOU major in?
Replies: 4
Views: 1078

Re: What did YOU major in?

I double majored in computer science engineering and computer engineering. I'm going on to do a Ph.D. in computer science since software engineering isn't really my thing, but both majors get you into good companies such as Google, Apple, Microsoft, and Qualcomm. The choice of school plays a heavy r...
by kmatzen
Sun Apr 11, 2010 6:02 pm UTC
Forum: Computer Science
Topic: Go complexity classes with different Ko rules
Replies: 2
Views: 2277

Re: Go complexity classes with different Ko rules

Sorry, I'm not familiar with Go too well, but I don't think that Go without Ko has been proven to be in PSPACE. I think it is still only PSPACE-Hard. Also, isn't Go with Ko more specifically in EXPTIME rather than EXPSPACE?
by kmatzen
Wed Jan 27, 2010 5:45 am UTC
Forum: Coding
Topic: Have you written a game?
Replies: 58
Views: 6120

Re: Have you written a game?

I took a video game design course last semester that I thought was a lot of fun, but also a ton of work. It breaks down to three weeks for a 2D game, three weeks for a 3D game, and seven weeks for a final team project. The hardest part was coming up with fun ideas for games with those three week pro...
by kmatzen
Thu Jan 07, 2010 2:30 pm UTC
Forum: Coding
Topic: Why are HDLs so extremely different from everything!?
Replies: 13
Views: 1780

Re: Why are HDLs so extremely different from everything!?

I always thought HDL was somewhat simpler than a high level language when starting out. There really is very little abstraction so the engineer knows exactly what is going on and has a fairly good idea of what will happen after synthesis as long as no constraints are violated in the design. Furtherm...
by kmatzen
Sun Jan 03, 2010 2:19 am UTC
Forum: Computer Science
Topic: Google OS for Old People?
Replies: 54
Views: 8999

Re: Google OS for Old People?

lulzfish wrote:HAHA
It has a trackball, wtf.
At least use standard hardware, weird mice will only confuse them more.


For many older individuals with arthritis, a trackball is much easier to use.
by kmatzen
Tue Dec 22, 2009 1:31 pm UTC
Forum: Computer Science
Topic: Which problem has the highest computational complexity?
Replies: 25
Views: 3374

Re: Which problem has the highest computational complexity?

What about factoring large prime numbers? O(1)? Integer factorization is expected to be outside P. Anyway, intuition seems to say that O(1) is not feasible since that might imply precomputing the factorizations, but since the integers are countably infinite, this cannot be done (the TM's tape is in...
by kmatzen
Wed Dec 02, 2009 5:55 pm UTC
Forum: Coding
Topic: getting integers from command line
Replies: 7
Views: 971

Re: getting integers from command line

there's almost never a good reason to subject yourself to using *scanf. I don't understand. atoi will return 0 upon failure to parse, and INT_MIN or INT_MAX if the value is out of range. sscanf will return the number of tokens that it could successfully parse. If you use atoi, there's additional er...
by kmatzen
Sat Nov 28, 2009 5:29 am UTC
Forum: Coding
Topic: A rule-based language?
Replies: 15
Views: 1899

Re: A rule-based language?

Actually, what you are describing looks less like rule based programming and more like event based programming. IE. This happens, do this. Rule based programming is more like This has happened, and this has happened, so this should happen which causes this to happen. I'm not sure there is quite the...
by kmatzen
Thu Nov 26, 2009 1:25 am UTC
Forum: Coding
Topic: A rule-based language?
Replies: 15
Views: 1899

Re: A rule-based language?

There's also CLIPS which is a forward-chaining rule-based system. It was developed by NASA to keep track of procedural checklists and diagnostics for shuttle launches. It has an interactive interpreter that makes it easy to play with. There's also a Python binding so that you can embed a rule-infer...
by kmatzen
Wed Nov 25, 2009 6:09 am UTC
Forum: Coding
Topic: Regular Expressions
Replies: 15
Views: 1744

Re: Regular Expressions

> It's most likely that the instructor just has no idea of the limitations of regexes. It's not a limitation of regular expressions. The language described above is regular. Maybe the instructor is testing your knowledge of equivalence between DFAs, GNFAs, and regular expressions. You could construc...
by kmatzen
Tue Oct 20, 2009 6:00 pm UTC
Forum: Coding
Topic: What to do with Lisp?
Replies: 25
Views: 4009

Re: What to do with Lisp?

If you want some reading material to get you in the mood for Common Lisp, I recommend Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp by Peter Norvig. This is where I first learned the language. http://www.amazon.com/Paradigms-Artificial-Intelligence-Programming-Studies...
by kmatzen
Sun Oct 11, 2009 6:07 pm UTC
Forum: Computer Science
Topic: Understanding the concept "learning" in Neural Networks
Replies: 9
Views: 2742

Re: Understanding the concept "learning" in Neural Networks

You understand about hyperplanes and such? The MLP "just" divides up the input space into cells and assigns labels to those cells ... it's just one big high dimensional voronoi diagram really. That's... possibly the worst explanation of a NN I've ever seen. That's exactly what we are taug...
by kmatzen
Wed Oct 07, 2009 6:34 pm UTC
Forum: Computer Science
Topic: What can i do with a computer science degree?
Replies: 31
Views: 64398

Re: What can i do with a computer science degree?

skelterjohn wrote:As in, without programming you cannot do computer science. So, you weren't being contradictory.


Computer science was studied long before the programmable computer existed...
by kmatzen
Tue Oct 06, 2009 2:49 pm UTC
Forum: Coding
Topic: Unit testing, databases and determinacy
Replies: 16
Views: 1785

Re: Unit testing, databases and determinacy

Most of the time, real test code is far longer than the code it is testing...
by kmatzen
Sun Sep 20, 2009 4:50 pm UTC
Forum: Coding
Topic: compilers...which ones the right one
Replies: 7
Views: 1377

Re: compilers...which ones the right one

I plan to work in java and C++. (not within the same program obviously) It's not obvious since you can call native code from managed code with the Java Native Interface. I would just go with the GCC which contains gcj for Java and g++ for C++, if you are on a Linux platform. For Windows, use the of...
by kmatzen
Fri Sep 18, 2009 12:01 am UTC
Forum: Coding
Topic: First programming job
Replies: 39
Views: 5507

Re: First programming job

Did/do you work for Microsoft or do other companies also call it dogfooding? "Dogfooding" is a common term in the tech industry. Dogfooding was originally a term that a test manager at Microsoft coined in 1988. I had only even heard it while at Microsoft and so I didn't know if it caught ...
by kmatzen
Thu Sep 17, 2009 12:45 pm UTC
Forum: Coding
Topic: First programming job
Replies: 39
Views: 5507

Re: First programming job

Parsifal wrote:Eat your own dog food!


Did/do you work for Microsoft or do other companies also call it dogfooding?
by kmatzen
Sat Sep 12, 2009 2:42 pm UTC
Forum: Coding
Topic: C# List.Sort() problem witn v and w [Solved]
Replies: 6
Views: 1380

Re: C# List.Sort() problem witn v and w

Can you provide a sample input and output set as well as your full code, not just the trivial snippet you posted? If you omit the IComparer in your call to sort, it should use the default comparer for a string. Something elsewhere in your code must be causing an issue.
by kmatzen
Fri Sep 11, 2009 2:53 am UTC
Forum: Coding
Topic: First programming job
Replies: 39
Views: 5507

Re: First programming job

I just do internships each summer. It's gotten me pretty far at this point.
by kmatzen
Tue Sep 08, 2009 12:41 pm UTC
Forum: Coding
Topic: C and C++ compiler for windows
Replies: 15
Views: 1622

Re: C and C++ compiler for windows

Here are some instructions we use for Visual Studio in order to get as standard behavior as possible. Supposedly, according to MSDN, even putting a .c file in the build path will automatically build it as C89. http://www.engin.umich.edu/class/eecs381/progenvs/MSVSNotes.html Why can't you just write ...
by kmatzen
Sun Sep 06, 2009 12:26 am UTC
Forum: Coding
Topic: C++
Replies: 15
Views: 2208

Re: C++

Go for the book written by the creator himself. http://www.amazon.com/C-Programming-Language-Special/dp/0201700735/ref=sr_1_2?ie=UTF8&s=books&qid=1252196613&sr=8-2 I hate this book with a passion since it keeps noting the point, "this may look like bad style, but an experienced C++ ...
by kmatzen
Sat Sep 05, 2009 3:55 pm UTC
Forum: Computer Science
Topic: Hacking Wifi
Replies: 4
Views: 2244

Re: Hacking Wifi

I'm not sure if you can get the wireless key, Sure you can. OP just hasn't been Googling well enough. Just try 'crack wep.' It will get you what you need within the first few links. Windows would be preferred, because my inner nerd have never taken to linux ever since it refused my one wireless car...
by kmatzen
Fri Sep 04, 2009 8:38 pm UTC
Forum: Computer Science
Topic: What can i do with a computer science degree?
Replies: 31
Views: 64398

Re: What can i do with a computer science degree?

Love programming. Love it, live it, breath it, and really feel passionate about it. It depends. There are career choices in CS related fields that require just as much technical knowledge, but don't require programming at all. From what I've experienced, they tend to pay more as well, but are harde...
by kmatzen
Fri Sep 04, 2009 7:48 pm UTC
Forum: Coding
Topic: Writing an Open Source Operating System
Replies: 27
Views: 3779

Re: Writing an Open Source Operating System

As for the speed, if the VM's an interpreter you've got to figure that each instruction is handled by at least a pointer addition and a subroutine call. This alone makes the program execution several times slower. Then you figure all those jumps also blunt the processor's ability to pipeline instru...
by kmatzen
Fri Sep 04, 2009 7:18 pm UTC
Forum: Coding
Topic: Writing an Open Source Operating System
Replies: 27
Views: 3779

Re: Writing an Open Source Operating System

I'm sort of curious as to the reason for designing a new language for this OS. New languages are cool, but I'm wondering what constructs it actually provides that you can't already get in another interpreted language. You cited speed as a concern. How does your implementation differ from other inter...

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