Daniel Skoog

## 1751 Reputation

11 years, 343 days

## Have a look at the Gaussian Elimination ...

Here is a link to information on the Gaussian Elimination command: http://www.maplesoft.com/support/help/Maple/view.aspx?path=Student%2fLinearAlgebra%2fGaussianElimination

For a more step by step method, use the Gaussian Elimination tutor (http://www.maplesoft.com/support/help/Maple/view.aspx?path=Task/LinearAlgebraGaussElimination ) found under the Tools - Tutors - Linear Algebra - Gaussian Elimination menu.

## Some issues with your code....

First, when you build your pde system using the 'for k' loop, you don't use the k variable at all and thus don't properly build your grid of values and set up the system.  That's why the output just repeats the eq(i,j) system over and over.  I would look over this call and perhaps even set up a secondary for loop to find values over both i and j for values k and say, l.

Your call for the variable X is fine.

The first two of the five lines that you are wondering about set up the boundary conditions, which absolutely need to be specified for the finite differencing to find an exact solution. Without these values, you can have any number of solutions.

Fsolve is used here to approximate a numerical solution for the system.  These lines are not necessary for the final calculations, but are a useful resource to compare your final solution to (You can see how this is used in the example worksheet that you referenced).

## Changing Maples fonts - Trying restoring...

Have you tried to restore the default text formatting?  This can be done by going to:

Format -> Manage Style Sets

and select “Default Maple Style Set”.

If this restores the output, maybe you applied some incompatible formatting to the text.

For more on formatting text, see the following link: http://www.maplesoft.com/support/faqs/detail.aspx?sid=87675

## Simple Random Walk in Maple Code...

I would begin by defining a for loop to create your data.

Inside the loop you can specify an array for your values for x, where x[i+1] is found by adding the resultant of your if statement to x[i]. I would also start the loop at x[1]:=0.

For your plot, I would define an index variable, say y, which you can also increment in your for loop.

Also, you can specify your p and q variables to be whatever values you'd like, and the u:= rand ( )/10^12 command would be of use.

Once the for loop has created your data arrays, you can subsequently zip the two arrays together and plot the result.

Try this and I would be happy to assist you with your code.

## Forcing Half Angle identities...

Unfortunately, Maple does not have any easy way to convert trigonometric identities using the half-angle identities.

One method to force this output would be to do something similar to the following:

q:=sin(theta):

applyrule(sin(x::algebraic) = -sqrt((1-cos(2*x))*(1/2)), q);

## Trying adding in the dependent variable...

I was able to get the following to plot:

with(DEtools):

deqn1 := diff(x(t), `\$`(t, 2)) = -2*(diff(x(t), t))-25*x(t);

DEplot(deqn1, [x(t)], t = 0 .. 10, [[x(0) = 1, (D(x))(0) = 0]], stepsize = .1, linecolor = blue, thickness = 1);

I believe that you were just missing the list of dependent variables.

## Enable Anti-Aliasing...

You can enable or disable Font anti-aliasing under the Tools - Options - Display menu.

## Maple fits brackets to the expressions e...

There is no way to control the sizes of the brackets.  Maple adjusts the size of brackets relative to the largest item contained within the bracket. The bracket size fluctuations you are seeing are probably due to Maple adjusting sizes on the fly.

## Could be a corrupt install...

This could be caused by a corrupted install.  Try totally uninstalling Maple and reinstalling it.

You have more than enough RAM (Maple 13 recommends 512MB for Win XP).

If reinstalling doesn't work, try reinstalling the Java runtime environment (JRE).

## Try 1-D Math Notation...

Have you tried highlighting the text in your document and converting it to 1-D math notation?  This might give you a better picture of what's happening behind the scenes.

## Shift+Tab in Linux works in Maple 15...

Shift+tab to move to the previous input section will work in Maple 15.

## No shift+tab in Linux...

It appears that there is no shortcut key to move to the previous input region for Linux.

Also, there is no way to customize shortcut keys.

## Use the libgmp-3.dll from the GENERIC fo...

Hi there,

What you could try to do is to first backup the copy of the libgmp-3.dll file in the bin.win folder (you could just rename it libgmp-3.bak) and then copy the libgmp-3.dll file found in the \Maple 12\bin.win\GENERIC folder to the bin.win folder and see if that works.

Cheers

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