chooseRandomSubmatrix -- returns coordinates for a random submatrix

Synopsis

Usage:

chooseRandomSubmatrix(n1, M1)
Inputs:
- n1, an integer,
- M1, a matrix,
Outputs:
- a list,

Description

This returns a list with two entries, first a list of random rows, and then a list of random columns. These specify a random submatrix of the desired size, n1.

i1 : R = QQ[x,y,z];

i2 : M=matrix{{x^2,x^3,x^4},{y^4,y^2,y^3},{z^3,z^4,z^2}};

             3      3
o2 : Matrix R  <-- R

i3 : chooseRandomSubmatrix(2, M)

o3 = {{1, 2}, {2, 1}}

o3 : List

Ways to use chooseRandomSubmatrix :

chooseRandomSubmatrix(ZZ,Matrix)

For the programmer

The object chooseRandomSubmatrix is a method function with options.