## Labeling graphs...

Hi All, I have the following graph: plot([(x/(2*sqrt(x)-3)),(-x+5)],x=-10..10,y=-4..6,discont=true, color=[red,navy], thickness=2); how do I a) label the two functions so that they are visible in the graph i.e. L=-x+5 beside the blue line and f(x)=x/(2*sqrt(x)-3)) in pretty text beside the upper red function? b) I wish for a dashed blue line (-x+5) instead of constant. Thanks in advance for any help :-) Robert

## Maple 10.02 update for 64-bit...

Does anybody know how to install the 10.02 update on a 64-bit version of Maple? -- Regards, Franky.

## Unassigning certain user variables...

We have an automated grading system and sometimes students assign values to variables that are useful in grading their assignments. In order to get around this I've been tinkering with the anames() command (specifically, anames(user)), but I cannot seem to get a usable list of "in use" variable names: Every time I try to get Maple to use the list that anames(user) returns, I get the evaluated variable and not the variable name. Example: >a:=4; >anames(user); 4 Does anyone know how I can get a usable list of variable names that have been assigned values?

## How to create random matrices with constraints?...

Hello Maple insiders, I'm still learning to get along with Maple (version 10.01). Currently, I would like to have a small procedure which creates a random matrix of arbitrary dimension with complex floats. However, the generated matix, say A, has to fulfill the following conditions (because it should be a valid physical density operator): 1.) A is hermitian 2.) A is positive semidefinite, together with 1.) this should mean that A has only real and nonnegative eigenvalues 3.) A should have trace equal 1 With the randomly generated matrices I would like to cover (reasonably uniformly) the set of all possible matrices with the above constraints.

## 3D polar contour surfaces with colour superimposit...

Hi, I would like to be able to plot a 3d surface of one variable, with another variable in colour on that surface. This plot should have a legend for the colour variable. At a stretch, I would also like to have all of this in polar co-ordinates, with polar axes and without having to write a transform myself. Is all this possible! cheers

## Global Optimization toolbox...

Hi, I am using the global optimization toolbox to minimize a matlab function as follows: restart; > (Matlab:-evalM)("cd 'C:/Documents and Settings/user/Maple'"); > mat2map1 := proc(a, b) local Res,res; Matlab:-setvar(\"a\",a); Matlab:-setvar(\"b\",b); Matlab:-evalM(\"result = mat2map1(a,b)\"); Res:=Matlab:-getvar(\"result\"); res:=convert(Res,float); return res; end proc; > with(GlobalOptimization): > infolevel[GlobalOptimization] := 3: > GlobalSolve(mat2map1, a = 0 .. 5, b = 0 .. 5); When I run this I get the following error message:

## Converting entire Maple worksheet into Fortran Cod...

Hi! I am trying to convert an entire Maple worksheet into Fortran code. At the moment, I have managed to convert a specific program using with(codegen): f:=proc(x) function end proc fortran(f) But this method can only convert one function at a time. Can someone please help me to convert an entire worksheet into Fortran or other languages? I have text and math in my worksheet, and I'm using 2D math in Maple 10. Thanks :)

Is there a way to track a thread without responding to it?

## How to get the index of some elements?...

I have two small questions: 1. Given a list L: L:=[false, false, true, true, FAIL,false]; and I want to get the positions of "FAIL" (in this case 5) and false (1,2,6). HOW could I get that? 2. Now, given another list Z with the same number of elements: Z:=[z1,z2,z3,z4,z5,z6]; I would like to replace the values of FAIL by 0 (zero). (in the way that Z became: Z:=[z1,z2,z3,z4,0,z6];) It is possible to do that without using "for do" commands? Thanks in advance, JJacques

## Prime Numbers...

Does anyone know if it's possible to discover the largest known prime number just using Maple 10 on a stand alone machine (PC)? Or does Maple 10 and or all of it's current additions / upgrades lack the computing power required to attempt this possible recreational task ? v/r, Dan

## 2 small questions.....

Hi dear Maple's gurus. I have the lists a and b: a:=[A, B, C] b:= [[K1,L1][K2,L2][K3,L3]] I want to add the each term of "a" in the intervals given in "b": sum(A from L1 to K1)+ ..+sum(C from L3 to K3). I tried with this procedure: > sums:= proc(a,b) local j,tot; tot:=0; for j from 1 to nops(a) do tot:=tot+sum(a[j], k=b[j,2]..b[j,1]); end do: end proc: >sums([a1,a2,a3],[[ku1,kl1],[ku2,kl2],[ku3,kl3]]); 1. Is there some more efficient way to do the same? 2. I would like also that the sums on a[j] under the following 2 join conditions: 2.1. assuming that a[j] is real and positive, and

## Numerator/ denominator......

Hi there! Assuming that I have the following fraction: fr1:= (x+1)/(x-1); I have the following 2 questions: 1. with which command could I take only the numerator "(x+1)"? (and for the denominator?) 2. Is it normal that whattype(fr1); returns a star * Thanks in advance for your answers, Jean Jacques