## 24 Reputation

12 years, 101 days

## Express Matrices Using Specific Basis...

Maple

Hi all,

I am considering a scenario in which I have, for example, four matrices, A, B, C, and D, which form a basis for all of the (numerical) calculations I am doing.  (For example, A + B = i*C, etc.)  Right now, if I add A and B, I get a matrix back whose elements are i*C, but I cannot get Maple to express it as i*C.  As a simple example, let:

A = (1 0 // 0 1 )

B = (0 1 // -1 0)

C = (i i // -i i)

Then A + B returns (1 1 // -1 1); I'd like for Maple to "intelligently" give iC.  So...how can I get Maple to expand a given matrix (A+B) in terms of a particular basis (here, simply C)?

Thank you.

## Defining Specific Spacetime Vector...

Maple

Hi all,

I am doing some rather complicated four-vector manipulations, which I would like to do with maple using the Physics package.  My problem is this: I can't figure out how to define a specific four-vector.  For example, one of my four-vectors is (p,0,0,p), while another is (p cos(theta), 0, p sin(theta), p).  Here's my attempt:

with(Physics);

Coordinates(X,quiet);

Define(P1[mu](p,0,0,p));

**Checking the components using e.g. P1[1...

## Evaluate integral with polynomial in the...

Maple 14

Hello all,

I'm trying to evaluate the integral (on Maple 14):

int(lambda/(A+B*lambda)^2,lambda=0..1) assuming A::positive, B::positive;

Maple cannot evaluate the integral, but returns the function call.  However, if I try to evaluate this in Mathematica, which I also have access to, it can evaluate it.  (The result is -(B+(A+B)ln(A/(A+B)))/B^2(A+B), if anyone is interested.)  I was wondering if there's something I'm doing wrong with the...

## Plotting Systems of Equations...

Maple

Hello all-

I have a system of equations, something like:

X1+X2+X3=1

and then I have seperate equations such as:

X3=T*X1^2*exp(.12/T) and so on

I'd like to make a plot of X1,X2,X3 as a function of T.  How can I do this?