## operation on a function of time...

Hello - this is a novice's question: Consider the following: > E1 := a = b > E2 := b = c > eliminate({E1, E2}, {b}) [{b = c}, {a - c}] So this works. > E3 := a1(t) = b1(t) > E4 := b1(t) = c1(t) > eliminate({E3, E4}, {b1}) Error, (in eliminate/recursive) invalid subscript selector What should I do in the second set above to eliminate b1(t) and get the result a1(t) = c1(t)? Thanks.

## pdsolve with point-by-point initial condition...

I'm numerically solving, using pdsolve on Maple 9, the diffusion-recombination equation. I'm interested in the long time behavior after a very short time excitation pulse. Ideally, pdsolve would have the capability to use a small time step for the initial part followed by a larger time step later. Otherwise, I could take the result of a calculation with a short time step as an initial condition for a calculation with a long time step. If anyone knows how to do either of those things, I would be grateful. Thanks, Richard

I have Maple 10.04 running on my PC. The Maplesoft product update site says Maple 10.06 update is available. Do I have to install 10.05 update first? Or can I go from 10.04 to 10.06 directly?? Thanks in advance !

## 1d phaseportrait...

Hello everybody I need to draw a phase portrait for the one-dimensional linear independent equation(just the arrows in axe X) Help me, please!!!

## Augmenting a matrix...

> Suppose I create a matrix as follows:

> Now I want to make it a 4 x 3 matrix by adding a specific row vector on top. The approach below doesn't work.

> ## Simple question about increasing the size of a Mat...

Hi I pretty new to Maple and I have the following question. I make some calculations and out pops a number of values I am interesting. This is done several times in a loop (which I don't know the number of iterations of). Now, I would like to save these values so I can use them later on. My idea was to put everything into a matrix, and increase the size of it during runtim. I.e. initialize M for 1 to 5 do some calculations that return a and b change M so that M equals the old M with a and b added as last row end do How do I do this?

## system of nonlinear equations...

Hello, I am quite new to Maple and I am trying to solve a system of 3 non-linear equations in 3 variables (A,zp,zh). I have tried the solve command, but after waiting few hours I have decided to stop the computation. Could someone help me with this? The system is as follows eq1 := 1/(-138.8888889/(24000000-50/3*zh)^1.5-.50/zh^1.5-122.7222223/(-8640000+47/3*zh)^1.5)*(5.465600000*A/(1+zp)^.5e-1 +(-16.66666667/(24000000-50/3*zh)^.5+1.0/zh^.5+15.66666667/(-8640000+47/3*zh)^.5)*(.3e-1+.3*A))=0; eq2 := .4879000781e-6/A*(1+zp)^2.05*((-1952000.00*A/(1+zp)^1.05+50/3)*(.3e-1+.3*A)-10.93120000*A/(1+zp)^.5e-1

## Stochastic paths - Brownian motion, multiple graphs,...

by: Maple
Hi everyone, I am an undergraduate studying Stochastic Financial Modelling. I am currently writing up a simple brownian motion as shown on the attachment. I have difficulty in simulation a number of these paths and displaying 5 or so of them on the graph with the average path of all simulated paths. In this case, i would expect the average to be a straight line along the axis. Can anyone help me with this as i am only a novice in maple programming? Thanks, Steve

## Identifying an assumed variable...

Hi: In one part of my calculation, I need to assume some properties for a variable; later on, the assumption is no longer needed so I clear the variable. After that, I cannot manipulate any of the previously calculated expressions containing that same variable. Here is an example. How do I get around this? I really need to clear the variable for other reasons. Thanks Mike restart;assume(n>0); > test:=-5/81*n^5+b*n^4+c*n^3+d*n^2+e*n+f; 5 5 n~ 4 3 2 test := - ----- + b n~ + c n~ + d n~ + e n~ + f 81

## Collapse document block...

The enclosed file has 2 document blocks. As far as I can tell, each block is identical except for the name of a procedure defined in it. When I go into Block A and select Format/Collapse Document Block, the procedure does not disappear. When I go into block B, it does. I'd appreciate it if someone could tell me why the difference. -Thanks View 2292_Georgeworksheet15.mw on MapleNet or Download 2292_Georgework

## Live Output in text?...

In the file I just uploaded, Georgeworksheet14.mw, the final statement is a text statement which has had two matrices copied into it. These matrices were copied from the output of equation 3). Is there any way I could make this 'live'. In other words, is there any way I could make it so that the matrices displayed in the last statement would change if the output of statement 3 changed? Also, I was forced to put the statements about the ZZZ matrices at the bottom of the worksheet because when you click the T (text) button, a new document block is always created at the bottom of the file. If I had wanted to put the statement about the ZZZ matrices right under equation 3), is there a way to have done this?

## animate 3d...

hi; using the animate3d command i would like to create a kind of reference plain, i.e. i would like to insert a plain at a certain value to figure out at which "point" the animated surface cuts through this reference plain. it should look like the static version shown in the linked worksheet: View 1682_cp solution.mw on MapleNet or Download 1682_cp solution.mw
View file details

## Trimming an array...

Hi friends, In my maple procedure I m calculating large amount of point then I m plotting them. Although I don’t know how many points will be calculated, I have a logical upper bound for number of points. I was using the method 1: ``` for i from 1 to N do if something is okey then x := ... y := ... data := [op(data), [x,y]]: end if; od: ``` but I have relalized that this is really slow. Then I started to use Method 2: ``` data := array(1..N): j := 0; for i from 1 to N do if something is okey then x := ... y := ... j := j + 1; data[j] := [x,y]: ```