## Setting the default directory...

I wish to set the default location for the "backup files" so they don't clutter my \$HOME directory. It seems to me that this should be an easy thing to do but I can't find any reference in any of the documentation sources. Everytime I use Maple and quit my home directory is littered with as many as 45 small files which (I presume) are intermediate save files from a session. I don't mind having the program autosave but can I assign this location to some special scratch folder? OS: Mac OS 10.4, G5, Maple 10.

## Functional Derivative...

Hi; Could somebody please let me know about finding functional derivative of H respect to m where, >restart; >H:=int(u(x)^3+u(x)*diff(u(x),x)^2+2*u(x)^2,x=-infinity..infinity); >m:=u(x)-diff(u(x),x\$2); by using Maple? Thanks a lot Sayed

## problem with @ operator and subscripted variables...

Note first that @ works as designed for a function named f: restart: > f:=x->x+a: > (f@f)(x); x + 2 a But if I name the function f[1] it doesn't work. > restart: > f[1]:=x->x+a: > (f[1]@f[1])(x); (2) ((f[1]) )(x) On the other hand if I have two functions named, respectively, f[1] and f[2] then it does work. > f[2]:=x->x+b: > (f[1]@f[2])(x); x + b + a Is this a bug? Or am I missing something? --Edwin >

## Maple 10 Commands...

How would I enter in a derivative problem such as f'(3) when f(x)=x^2+8x+4 into maple 10?

## I need help evaluating a very specific limit of a ...

I need some help!! I need to show the following using MAPLE 9.5: Suppose I have a symmetric 4 x 4 matrix whose entries are all positive, called A. Suppose also that I have a random vector in R4 whose entries are also all positive, called c. I already have a routine to determine the largest absolute eigenvalue of the 4 x 4 matrix, called L. I need to show that the vector v, calculated as follows: v = lim[(A^n)c / (L^n)] as n tends to infinity is an eigenvector of A, with eigenvalue L. Any suggestions??

## help me...

How do I take sin of a matrix?

## Does Maple 10 plot sequences?...

How can I plot a function with an integral domain? For example how would I plot f(n) = 1/n for n=1..10 or g(n)= n! for n=1..10 or h(n) = g(n)-f(n) for n = 1..10? Any help would be appreciated. Tom

## Coeffiecent replacement...

I'm trying to write some code that will rewrite an expression of the form R = expr => newExp = 0 Then take all the coeffiecents of newExp with respect to the variables (var) and replace them with new coefficients of the form a.1, a.2 etc and finally put it together with the variables again to obtain the new expression. This is the code i've got so far and it doesn't work, not used to working in maple so can't really figure out the problem... strRpm := proc(expr, var) local num, den, k, maxIndex, zeroform, R; num := numer(exd); den := denom(exd); zeroform = expand(R*den-num);

## Where is the problem in this restricted optimizati...

I want to maximize x*y*z subject to U= (10-x)*(10-y)*(10-z). My Lagrangian function is: L:= x*y*z + lambda* (U - (10-x)*(10-y)*(10-z)); # (I assume that values of x,y,z are between 0 and 10) assume(x>0,x

## A Maple equivalent to "fminsearch"?...

Does anybody know whether Optimization[Minimize] is the equivalent of matlab's "fminsearch"? If it is, then it will save me from having to move all my project work away from Maple =) Elaine

## Using implicitplot3d...

Hi, When I write the following commands.. I get only one surface in R3.. is not possible to add one option to have more surface levels (automatically)? implicitplot3d(x*y*z, x=0..10,y=0..10,z=0..10); implicitplot3d((10-x)*(10-y)*(10-z)^2,x=0..10,y=0..10,z=0..10); In fact, in contourplot we have one option contours=10 which allow us to draw the 10 contour levels.. Is not possible to do something similar with implicitplot3d?. Thanks in advance for your comments. JJ

## 3d plot using imported data points...

Hi, I'm trying to draw a 3D graph of some points that I have generated in Excel, so I need to be able to import the data somehow into Maple then be able to plot it. I can produce the data in two formats, the easiest is a grid with x values along the side and y values along the top, then the z values fill in the grid. Alternatively I can create 3 columns, x, y, and z, so that the number of rows is the number of data points I have. I've been trying this for hours and haven't got very far. I've managed to get the data into Maple (version 10) using the Assistant - Import Data option on the Tools menu, and this produces some kind of matrix of my data. However it won't let me plot it!! Any help would be much appreciated!