## 90 Reputation

5 years, 170 days

## Infinite summation problem...

Maple 2018
Hi !
I have several infinite sommations to evaluate. Maple 2018 on Windows 10 often gives me the solution in terms of hypergeometric functions. I know that the solution can be expressed in terms of sines and cosines.
I am not familiar with sumtools or Sumtools packages.
The convert (expr, StandardFunctions) or simplify (expr, hypergeom) commands do not work.

Here is an example of a sommation to evaluate.

My old version of Maple V release V (1997 version)  gives me the desired result with the same commands.

Is there a command that forces Maple to give me the solution in terms of sines and cosines ?

I don't have Mathematica. I hate Mathematica with its difficult syntax but I have access to a computer with Mathematica.
There is a "FunctionExpand" command which converts hypergeometrics into standard functions.
For the previous summation it works very well.

Thanks !
Réjean

## Is this recurrence equation too complica...

Maple 2018

Here's the recurrence equation I'm trying to solve and the weird answer that Maple 2018 gives me on Windows 10.

Out of curiosity, I started my old computer with  Windows 2000 and Maple V release V (1997 version).
I typed the same lines as before. I got the answer I was looking for immediately.
What's happening ?     What am I doing wrong ?

I am often excited by the the latest versions of Maple but recently I have been rather surprised by the things it cannot do.
When that happens, I remember the story of the guy who wants to sell a great watch to another guy.
"This watch is full of new gadgets:
gps, heart rate, body temperature, outside temperature, micro camera, voice recorder, email, internet ...

Only one problem . It doesn't tell time . "

Best regards .

Réjean

## 3 little annoying things ....

Maple 2018

1)  Copy/paste problem .

Looks like Maple is not able to copy/paste the output
from a summation command . Look at my example .
I have to use the  " lprint " command .
2)   Mysterious small box character .

Suppose I want to edit a command . I want to replace a character with a left bracket
(or right bracket or left accolade but strangely not the right accolade).
I put the cursor on the character and type the left bracket (or right...) .
The left bracket ( or right ...)  is inserted . Now when I try to delete the character,
a small box appear . The  character I am trying to delete is shifting to the right .
Like  I said , just a little annoying .

3)  Open file problem .

The first file I open in Maple with the  ctrl-o command , the "open file window" appears in
the center of the screen . All the others files I am opening , the "open file window"  show up
in the bottom left corner , top center or top right corner ... randomly .
Very annoying on a 27" screen . For this last one ,I am not shure  if it is a Maple 2018 problem
or a Windows 10 64 bits problem . I have few programs in my computer .
When I use Microsoft Paint or Wordpad ,I don't see this problem .

I don't know if somebody else can confirm those annoying things . If I am not the only one
then I am hoping the next updates or versions will fix that .

Thanks !

## Sorry, but it's a bug !...

Hi !
I made a program that solves a series of system of linear equations of increasing dimension.
Equations with rational numbers. I have a list of equations "liseq1" and a list of variables "lisvar1".
I use the following command :

solve(liseq1,lisvar1) ;

When the equation system reaches dimension 32, Maple gives me the following error message :

"Error, (in LinearAlgebra:-Modular:-IntegerLinearSolve) invalid arguments to iratrecon" .

It is an overdetermined system with 33 equations and 32 unknowns .
The variables are defined with the command:
x: = array (0..31) ;

I managed to work around the problem by replacing the variables with the following commands :

lissub: = seq (x[i] = x||i, i = 0..31) ;
lisvar2: = subs(lissub, lisvar1) ;
liseq2: = subs(lissub, liseq1) ;
solve (liseq2, lisvar2);

If you run the file I sent, Maple sometimes gives the desired answer but in a random way
because if you run the last 3 lines in a different order you will get the answer or the
error message .

Something remains in memory. Sorry, but it's a bug.
I have Windows 10, 64 bit with Maple 2018.2.
Regards .
 1 2 Page 2 of 2
﻿