## Lagrange multiplier maximum

by: Maple
As a newbie to maple, I was wondering how do I find the maximum of a equation under contraint. i can find some but for this one I can't ... and it's getting to me f=1000*x+7500*y under constraint: g=10000000-(20000*x^0.8)*y^1.2 and for f=(20000*x^0.8)*y^1.2 under constraint: g=125000-1000*x-7500*y Who do I find the maximum using MAple 10 !!!????

## 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)[1]; 4 Does anyone know how I can get a usable list of variable names that have been assigned values?

## 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:

## 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

## 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

## Maplet - Slider - Negative Values?...

Simple question: I can't seem to use a negative number as a minimum value for a slider control (in Maplet Builder)... Is this not possible? Thanks! Bryan

## Invalid evaluation of derivative (Maple 10)?

by: Maple 10

Create new document (or worksheet) with content below and execute it step by step: > restart; > Eval(diff(v(z),z),z=H)==eval(diff(v(z),z),z=H); Eval(diff(v(z),z),z=H)=diff(v(H),H) > v:=z->z*H; v:=z->z*H > value((1)); H=2H As you can see, result of eval, which in this case is equivalent to subs(z=H,diff(v(z),z)), at the right side of first equation leads to wrong final result :( This...

## solving nonlinear equations...

can i use maple to solve 15 nonlinear equations in 15 unknowns in the following form: T1^2 + 5(T1T2) + 6(T1T3)+ 8 (T1T4) + 7 (T1T5) + ....... -5 (T1T15) = 0 T2^2 + 3(T2T1) + 6(T2T3) -3 (T2T4) + 5 (T2T5) + ....... -3 (T2T15) - (T1T3) = 0 where T1 + T2 + T3 + T4 + ... + T15 =1

## Customizing the LaTeX output......

does somebody know how to tell maple to produce "a nicer" latex output? For example in workspace I get a nice fraction > y:=1/(1-x); y:=1/(1-x); but the latex command returns > latex(y); \left( 1-x \right) ^{-1}  I would like it to be something like \frac{1}{1-x}. My idea is that if maple knows how to print this as a fraction in the workspace, then the latex command could also behave like that. Any idea? Thanks in advance Jan

## Maple User Group Archive

by: Maple
The Maple User Group mailing list was once the main forum for asking questions and discussing Maple. Eventually the comp.soft-sys.math.maple newsgroup was proposed and the MUG list faded away. Some answers to specific questions are archived here, and all messages from 1998-2003 are available as digests.

I am looking for the JavaDoc of com.maplesoft.openmaple.* -- is it available somewhere? It looks like the API allows me to do DAG-based calls to Maple, but parts of that API appear undocumented :-( I am working with some people in Ireland who would prefer to pass Maple DAGs rather than strings, and it sure looks like the API allows it, but it isn't fully documented. Help!

## Just a variable...

Dear all: To point: It is possible to build a variable where I can have control of 4 groups of index around the variable, how i show above. G_INDEX1 G_INDEX2 VARIABLE G_INDEX3 G_INDEX4 I apreciate very much your help. best regards JADO