## Elimination of a variable from a set of two first ...

MAPLE.doc

I want to eliminate the variable u_x from the two equations attached in the document MAPLE.doc. Here u_x and delta are both functions of x. Is it possible to do it in Maple. If possible, how do I do it?

## Why does a minor change in a parameter cause the c...

The fsolve in the attached code took 45.615 sec to execute. For Delta >= 0.15 the execution time was only about 0.5 sec. For Delta = 0.12 and Delta = 0.11 the execution times were about 400 and 600 sec, respectively. Why does the execution time increase with orders of magnitude when I decrease Delta? And how can I speed up the process? Henning

## Maplet Builder Question...

I am "playing" around with the Maplet Builder and I am having some problems:
Let say I have three separate vector columns with data loaded in maple ie A, B and C.

i) I want the user of the maplet to be able to select ie highlight a vector from the three
available vectors which are presented in a drop down box.

ii) A button when clicked on plots the data in the selected vector.

How can I do this with the Maplebuilder??  I will need step-by-step instructions.

## How to remove Float(undefined) from plot structure...

My Maple plots contain strings like this one:

[HFloat(undefined),HFloat(undefined),HFloat(undefined)]

Let's call them "offending strings" or "errors", as they would most likely have been avoided by more experienced users. These errors arise while creating odeplots. I suspect that these errors are produced by the option Events of dsolve each time a halt is triggered. This is mere speculation and besides the point of my post anyhow.

Maple seems to understand...

## point plot and colors...

The code below, which is a PLOT structure, seems to be one of the more efficient forms of specifying individual colors for each point in a 2D point plot.

My central question is: what plotting command will construct this?

```PLOT(CURVES(Matrix([seq([i,i],i=0..4)],datatype=float[8])),
STYLE(POINT), AXESLABELS("", ""), VIEW(0 .. 10, 0 .. 10),
COLOUR(HSV,
Array(1..15,[0.0,1,1,0.2,1,1,0.4,1,1,0.6,1,1,0.3,1,1],
datatype=float[8])
)
);
```

I know that I can call `plot` and pass the m-by-2 Matrix of point data, and specify style=point. But how can I pass in such a nice, efficient float[8] Array to specify the points' colors? I know that the float[8] Array is leaner than a long sequence of HFloats. But even in the simpler case of just two points: how can one pass the `color` option just once to specify the colors to be used for each of the points?

Oh, in case anyone's interested, another old-fashioned (but terser) was to get such a float[8], C_order Array is with the `hfarray` command.

## Statistics:-PDF() fail with function of a random ...

Dear,

I (used Maple12) tried to find the PDF(Y,y) when Y= tan(X) or Y= sin(X) but those cases give FAIL or wrong result

===============================

restart; with(Statistics):
X:= RandomVariable(Uniform(-Pi/4,Pi/4)):

PDF(2*X+1,y) ## work well

but:

PDF(tan(X),y); # failed
...

## exec() and fork()...

Hello! I need to have two simultaneous processes: first is maplet and second .exe. I tried fork and exec but there were errors:

Error, fork (exec) not supported on this platform.

What can I do with it? OS: Windows7 x64

Using Maple 11.

## How to solve for I(s)/V(s) from (Ls+R+1/Cs)*I(s)=V...

(Ls+R+1/Cs)*I(s)=V(s)  How can I solve for I(s)/V(s) Please so me steps. Thanks in advance

## How to test for convexity...

Hi,

I'm using Maple 14 and have a function in several variables, which I want to minimize. As far as I know, to guarantee that NLPSolve (from the Optimization package) is really finding a global minimum, this function must be convex.

What is the best way to test for convexity in Maple?

Carlos Mallen

## how do i plot multiple plots in a graph?...

i am plotting multiple plots in one graph using the following commands. This has been successful for a different function but it doesnt work at all for the typed function. can you pinpoint my mistake? maple sheet is attached as well.

` `
`> restart;> w(r):=1+(S)/(2)*[(r^(2)-1)/(2)-4*ln(r)]-(b*S^(3))/(4)*[(r^(4)-1)/(4)+128*((1)/(r^(2))-1)-6*(r^(2)-1)+48*ln(r)]+(3* S^(5)*b^(2))/(8)*[80*(r^(2)-1)-5*(r^(4)-1)-640*ln(r)-640*((1)/(r^(2))-1)+(r^(6)-1)/(6)+256*((1)/(r^(4))-1)];`

## GetEquation command line...

How do you get equation from user in middle of a procedure? I tried to use the GetEquation of Maplets[Examples] but I cannot make a function out of it. The sheet is something like:

## how can i calculate the sum of digits after a comm...

Hi

i need help

i want calculate the sum of digits after a comma

## lenght of ARC !!!...

My function is f(t)=(4bcos(t)^3,4bsin(t)^3).

I need this function's lenght of ARC and fonction of lenght of ARC.  t=0.  Maybe i need this graphic.

## Minimize VaR with LP...

I want to minimze VaR (the 5th percentile for the return distribution) with LP.
However, the way I have specified the problem does not work for some reason, why?

restart:
with(Optimization):
with(LinearAlgebra):

nstock := 20:
n := 15:

R := RandomMatrix(n, nstock, generator = -15 .. 15, outputoptions = [datatype = float[8]]):
W := Matrix(nstock, 1, [seq(w[i], i = 1 .. nstock)]):
data1 := Array(Multiply(R, W));