## Maple Questions and Posts

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

The attached file solves a system of equations in a couple of seconds in maple 9.5 But in classic worksheet maple 10.04 after many minutes it gobbles up gigabytes of memory and then ends with an error. The file belows shows the details but it has the form sys:={eq1,...eq22}: solution:=solve(sys,{var1,...var22}): Any comments very much appreciated. Download 2129_No Solve.mws

## help big time newbie...

i have a equation such as : f(qa)= 75-0.4*qa^1.5 i would like to know how to know the maximum of qa when qb is 0 and vise versa. also how to plot a slope a a given point for example qa = 0 or 20.

Hi, My name is Jennifer.Iam new to Matlab programming.Iam working on reducing the noise content in audio communication. Iam using Hamning codes for the same.I have a sample code with me,which iam unable to upload because it says that maximum file size exceeded.Iam unable to understand how it works.Can someone please explain me how the code is written,what it means and what the different plots mean and how to read them? I have trouble especially with the plots trying to understand them. Being a beginner,Iam having a lot of trouble trying to understand.Iam trying to read Matlab tutorials at the same time but I have to finish up this work soon before the deadline.So can anyone be kind enough to help me through this please? My email id is jennifer22cute-single at yahoo.com

## question on an exercise...

hi! i need your help, i am a student of economics and i have to solvean exercise in maple but i can't do the last point;i have stopped just at the end of the exercise! please if anyone can do it orgive a help how to solve it i will very grateful.the exercise is how to calculate the days between two dates.i can't attach the file because the total file exceeded thank you

## arrow...

How do i make a curved arrow in maple 9.5 to show a rotaton arround an axis in a plot?

## Seemingly simple convolution takes forever... why?...

I have a maple worksheet (attached) that calculates a 2-D convolution. Should be easy, I would guess. The convolution of a gaussian and a gaussian is very fast-- this has a simple analytical result anyway. A gaussian and a sinc function can take a couple of minutes... and a gaussian and a bessel function takes longer than I can allow! I think I must be missing something here. I've tried various things, interchanging "int" and "Int" for the integration, and also seting digits to something low, by using evalf. Sometimes it just maxes out all available memory before grinding to a halt, in other trials it will allocate about 300 MB and churn for hours. The worksheet is attached. I'd appreciate the advice.

## Working with EPS graphics...

Do any of you have any graphics software suggestions for adding lines, text, etc. in EPS plots generated by Maple? I have have mainly only used Photoshop for editing plots while working with LaTex, but I have increasely become dissatisfied with the results. Any suggestions? Thanks, Phil

## printing out once...

> procA :=
proc ()
print ("Hello");
2;
end proc:
> procB :=
proc ()
local i;
i := procA();
end proc:
> procA ();
"Hello"
2
> procB();
"Hello"
2

The main that I want to get is:
if it was executed procA, it should show "Hello" text and the 2 number, but if it was executed procB, it should show only the 2 number, it shouldn`t show "Hello" text.
What can I do to get this special result in procB?

## A bit of humour...

by: Maple
maplesoft.com mechofmat.com

## local vectors and matrices within a procedure for ...

Hi,

I am trying to ease my c coding work with the "CodeGeneration" tool in maple. The Idea to generate ready to use functions is quite thrilling.
In my attempts to generate code I entontert two problems.
First it seems to be impossible to assign local vectors to vectors passed in the argument list:

> MapX := proc (X\_out::Vector(2), X\_in::Vector(2), PRO2RO::Vector(2))
> local X\_t :: Vector(2,0), i;
> X\_t := PRO2RO;
> X\_t := PRO2RO*10;
> X\_out := X\_in + X\_t;
> return;
> end proc;

here the assignment X\_out := X\_in + X\_t; is not recognized.

## Execute Execution Groups depending on the value of...

Hi, is it possible to define a variable for example "x" upon which it depends whether an execution group in a worksheet will be excecuted when clicking on !!! (Execute whole worksheet) or not? Illustration of the idea: x:=1; if x=1 then execute execution group else do nothing end if; I am thankful about any ideas!

## Dividing polynomials...

I have an expression, lets say x^2+ y*z^2+y^3 and I want to divide it with x*y and I want the output to be x/y+z^2/x+y^2/z How do I do this?

## "assume", "type" and "if"...

Can anyone tell me why "type" answers "false" and why do I get an error message, from the following simple code sequence (Maple 10)?

Thanks

restart;
> testp:=proc(m);
> if (m=0) then 0;
> elif (m>0) then 1;
> elif (m<0) then -1;
> end if;
> end proc;
> assume(n,posint);
> type(n,posint);
> is(n,posint);
> testp(n);
> testp(-1);

testp := proc(m)
if m = 0 then 0
elif 0 < m then 1
elif m < 0 then -1
end if
end proc

Originally n, renamed n~:
is assumed to be: AndProp(integer,RealRange(1,infinity))

false