## 40 Reputation

10 years, 281 days

## Replacing Text From fprintf...

Maple

I'm using maple to write text to an external text file. My code is

f := x-> arcsin(x);

file := "C:\\example.txt":

fopen(file,WRITE,TEXT):

fprintf(file,"%a",f(1)):

fclose(file):

The problem is that the output in my file example.txt reads "1/2*Pi" and I'd like it to be "1/2*pi". In other words, is it possible to have maple scan my file and replace the occurances of "Pi" with "pi"?

## Importing Matrices into Maple ...

My question is very similar to this question however my .txt files are in a different format.

I've generated a .txt file with Macaulay2 that looks like this

| -1 0 9  -17 4   |

| 1  2 -3 7    17 |

I would like to import this file into maple and define a matrix M as this matrix. Is there any way to accomplish this?

## Reordering the columns of a 2 by n matri...

I'm trying to write an algorithm that arranges the columns of an arbitrary 2xn matrix counter-clockwise starting at the point closest to (1,0). For example, when I input the matrix

Q := Matrix([

[ -1 ,  0 ,   0 , -1 ]
, [  0 ,  1 ,  -1 ,  0 ]

]);

into the algorithm, I would like the output to be

R := Matrix([

[  0 , -1 , -1 ,   0 ]
, [  1 ,  0 ,  0 ,  -1 ]

]);

Is there any package that could help me with this?

## Listing the Unique Columns of a Matrix...

Maple

I have a matrix with repeated columns

with(LinearAlgebra):

Q := Matrix([1,1,1,0,0,0,-2,-1],[0,0,0,1,1,1,0,-3]);

I'd like to write a loop that defines u[1],...,u[n] to be the unique columns of Q. Is there a way to do this?

## Defining a Function of a Pre-Defined Num...

Maple 17

I'm writing some code that computes a positive integer N and I'd like Maple to define a function of N variables. I've tried writing

f := (seq(t[i],i=1..N))-> MY EXPRESSION;