Maple 18 Questions and Posts

These are Posts and Questions associated with the product, Maple 18
 

 Good morning all.
Consider $A=[a_{i,j}]$, a $18\times 18$ matrix (for example); the integer entries are randomly chosen in $[[-5,5]]$ (for example). In general, $A$ has distinct eigenvalues.

I seek the eigen-elements of $B=Transpose(A^{-1})A$ with $10$ significand digits (for example); in general, $B$ is diagonalizable ($P^{-1}BP=D$, a diagonal complex matrix). I use the command $evalf(Eigenvectors(?))$.

Many randomized tests require working with hundreds of Digits. The worst one requires $629$ digits!! Moreover (in this test), when $Digits:=400$, the condition number of $P$ is $10^{118}$ and , with $Digits:=619$, the condition number drops to $376$.

I am surprised by this instability. In particular, this method seems to be unusable when $n=100$.
Does there exist a method (using maple) which allows to solve the problem without dragging behind me a multitude of digits ? (perhaps with iterations...)
Thanks in advance.

 

Dear friends, please I would like to ask for your help with the following problem: 

I have to compute some linear programming calculations. I thought it would be a good idea to perform them employing a parallel code. However, much to my surprise, the parallel code is slower than the single-threaded one. I enclose a worksheet sketching both codes with an example. Would you please tell me what it could be wrong with my code? 

Many thanks for your help.EXAMPLES.mws 

Please can you help me in resolving this error?

Here is the codeOptimal_control_model_of_DF_and_LP_2.mw

Hello,

I have a nonhomogeneous heat conduction problem, where the thermal conductivity, the density, and the specific heat of the
material are piecewise functions.

The thermal conductivity derivative has a discontinuity that causes a problem in the pdsolve command (see the first test).

To avoid this problem, I did a second test where the product rule was calculated directly.

Is there a better way to deal with this problem?

thank you

problem.mw

xE.mw

I integrate the expression maple but the result is large. How to furtherxE.mw reduce the size of the result? Also, what is dilog on maple?

u=a-(4*i*b)*(a*sinh(c)-2*i*b)/(a+2*i*b*sinh(c)), where b is a complex parameter, a is a real constant and, c=\sqrt(a^2-4*b^2)*(x+t/(2*b^2)), then how to calculate |u|^{2} on maple?

Hello there, 

Here is a set

thanks

Dear maple users,

Greetings.

When converting the maple figure into EPS format (for latex) which shows white patches.

How to avoid such patches.