22 lines
622 B
Matlab
22 lines
622 B
Matlab
function simplematrixbox( a, s )
|
|
% visualizes the effect of a matrix a on a set of vectors forming a box
|
|
% a: a 2x2 matrix
|
|
% s: a string plotted as the title of the plot
|
|
% this function is called by simplematrix2dtrafos.m
|
|
% this is a simple version of the more elaborate matrixbox() function.
|
|
|
|
x = [ 0 1 1 0 0 1; 0 0 1 1 0 1 ];
|
|
plot( x(1,:), x(2,:), '-b' );
|
|
hold on;
|
|
y = a*x;
|
|
plot( y(1,:), y(2,:), '-r' );
|
|
[ ev ed ] = eig( a );
|
|
ev = ev * ed;
|
|
quiver( [0 0], [0 0], ev(1,:), ev(2,:), 1.0, 'g' )
|
|
hold off;
|
|
xlim( [-2 2 ] )
|
|
ylim( [-2 2] )
|
|
title( s );
|
|
waitforbuttonpress;
|
|
end
|