## Maple Questions and Posts

##### These are Posts and Questions associated with the product, Maple

Hi everyone, I'm new here and I need some serious help. This may seems stupid to you but here it goes. A friend of mine has Maple 10 and I've done my homework with him. But At my school, they've got Maple 6 or something like that and my teacher is unable to see the worksheet that I've done.... Can you help me???

## color the background for text in a plot...

i want to label something in a PLOT structure with TEXT. the problems are that the POLYGON i want to label is (usually) dark. One might solve this by guesstimating the size of the label and putting a white polygon behind it. The problem with this is that text doesn't scale in the same way that polygons do, so when you enlarge or reduce the graph the "text box" no longer holds the text. is there an option for TEXT that will write the label on white? or some other way of doing this? also the text is of variable length (edge weights for a graph, actually). thank you for your help

## number of solutions...

Hi, I need to find how many solutions were found by solve or fsolve. I have solutions := fsolve(eqution,t) and I need to operate solutions in the loop, I have tried to make condition solution[i] <> NULL. It seems to work, but it print an error message(when i is higher then no of solutions). Is there any possibility, how to get no of solutions to bypass that, or any better solution? Thanks for your answer

## How to plot a vertical straight line?...

Hi, this is a really simple question but I just can't seem to find a solution, how do I plot a vertical line in maple such as x=10, everytime I try something it always plots the line y=10 and gives me a horizontal line. Thanks.

## Implicit equation plotting

by: Maple
Can anyone help me please?! Cash Reward! My program solves my implicit equation but i am having trouble getting more than one result, ie, varying one of the variables. The best i can do is make a loop which gives a table of results which requires individually copying the results across into Excel for anysort of graph. Ideally i want to be able to plot the results in Maple, for any variable. This is for my 3rd year engineering project, any help much appreciated. > restart; > with(LinearAlgebra): > # IMPACT OF A FLUID FILLED SPHERICAL SHELL ("NON-HERTZIAN") WITH A "HERTZIAN" BALL-

## How do I find the period of periodic continued fra...

Finding the period is simple enough, but gets really irritating once the number of terms in the continued fraction expansion gets large. I've scoured the help files and cannot find anything on it. All I have managed to do is right click on the output and convert it to a list. But then I don't know what the command is to find the number of elements in that list.

## Problem in Solving Non-linear PDE...

I am not able to numerically solve a non-linear PDE using "pdsolve". The problem seem to be arising due to non-linearity in the PDE. Once I remove the non-linearity (by removing a partial derivative in X below), the error goes away. The code and the error are included below: X:= Q(t,r)/(Q(t,r)+(0.75*diff(Q(t,r),r))); PDE:=diff(Q(t,r),t)+X*(diff(Q(t,r),r)*1.5*(0.03-r))+Q(t,r)*r=0; IBC:={Q(1,r)=0.01*r,Q(t,1)=10*(exp(1-t)-0.999),Q(t,0)=(exp(1-t)-1)}; ANS:=pdsolve(PDE,IBC,numeric,time=t,range=0..1,method=Box); Error, (in pdsolve/numeric/process_PDEs) selecting function must return true or false

## ImageTools Reading Images...

I'm trying to read an image into MAPLE as a matrix but I can't get the Read commmand to work. Is there some kind of working directory that I need to have the image in? Can someone give me some detailed examples on how to do this? ~Jacob

## about simulation code...

Hi, if equ:=y''+y'=9 how do can generate simulation code for maple code? on the demo "code generation"has this example. but I can't see it. thx for your help.

## Elliptic integral...

How do I make the evaluation of this Elliptic integral faster? >c12:=2*sqrt(2)*int(sqrt(3*t^2-2*t*(sqrt(2)+2)+2*sqrt(2)+3)*sqrt(3*t^2*(17-12*sqrt(2))+2*t*(29*sqrt(2)-41)-24*sqrt(2)+34),t=0..1): > evalf(c12,32); 1.5710166980738556513064017544723 - -28 0.24579031714044391948173350026764 10 I > Maple generated 152 pages of equations to solve this integral. This is how I generated this integral: http://www.getnet.net/~cherry/derive/circle1.doc I solved the problem using symmetric Elliptic integrals. Maple does not support symmetric Elliptic integrals.

## Basic question Re Maple 10 and stats...

Can anybody help me with this: Suppose you have a small set of values data:=[0.0630, 0.1050, 0.1560] and you're wondering what's the standard deviation of data with the "old" stats package you'll get with(stats): describe[standarddeviation](data) 0.03802630668 with the new Statistics package (which is supposed to replace stats) you'll get with(Statistics): StandardDeviation(data) 0.04657252409 The stats package will assume (unless told otherwise) that it must compute the standard deviation of a population, while the Statistics package will assume that it must compute the standard deviation based on a sample.

## Use 'if' within a spreadsheet...

I am using Maple 7 and displaying computations within a spreadsheet for more simple display. One area I have been stumped with is using the if statement within a spreadsheet cell. Something as simple as: `if FAIL then 3 else 5 end if` works great at a prompt but gives me a "System error," within my spreadsheet. Now, I know it recognizes the command because if I input the statement with legacy format: `if FAIL then 3 else 5 fi` It automatically replaces the "fi" with the new form of "end if". So why doesn't it work? Thanks,