MaplePrimes - answers and comments on Question, "mserver.exe has stopped working" on Windows 7 x64

At what point does the error occur?

Carl Love — Sat, 23 Mar 2013 18:45:44 Z

Does the error occur in CalculateMatrix or after? Put a print statement after the CalculateMatrix call to find out.

It is a system of linear equations. It would be much more efficient to solve it with matrix operations (i.e. LinearAlgebra:-LinearSolve). Would a floating-point solution be acceptable? That would use much less memory.

Why exact rational arithmetic?

Carl Love — Sat, 06 Apr 2013 17:44:56 Z

In your program, what is the purpose of the following lines?

if type(y, rational) = false then
y:= evalf(y);
y:= convert(y, rational)
end if;

In other words, why are you using exact rational arithmetic, even after floating point approximation?

I ran your code for m=50, and the answers have more than 10000 digits in the numerator and denominator. It could be over a million digits for m=300.

Updated hardware floating-point code

Carl Love — Sat, 06 Apr 2013 21:01:13 Z

Here (attached) is your code with my (minor) modifications to make it run in hardware floating point. I ran it up to size 512 in less than a minute, and got reasonable accuracy (norm of the residuals 1e-16 seems reasonable to me). Let me know if this fulfills your needs.

Markov_a2.mw

After, in the solve() function

wb_jerry — Sat, 23 Mar 2013 22:59:41 Z

Hi, Carl! Thanks for your help.

I have printed some information as you said and I'm sure the error occur after CalculateMatrix.

I will try to modify my programusing LinearSolve and see if it works. Thanks anyway.

It's doable

Carl Love — Sat, 23 Mar 2013 23:41:22 Z

@wb_jerry Okay, then the problem is almost certainly solvable. I ask again: Is a floating-point solution acceptable?

What do you mean by "anyway"? Didn't I help you?

Thanks a lot

wb_jerry — Sun, 24 Mar 2013 07:55:16 Z

@Carl Love

Floating-point solution is acceptable.

Of course you helped me a lot. Really sorry for the misunderstanding caused by my poor English.