plotting parts of plotmatrix via plot handles

Question

My code is the following:

A = [7 3 -1 1; -3 -9 3 7; -5 9 -7 -2; -2 4 -6 -2; 0 -3 8 2; 5 3 1 0; -10 10 -3 9; -6 8 9 -8; -6 2 -3 7; -2 2 2 -2; -9 0 -5 -1; 2 -5 2 -7; -2 10 -3 9; -5 -9 9 2; -8 7 6 -8; -3 -10 8 10];

[H,AX,BigAx,P,PAx] = plotmatrix(A);

graphics_toolkit fltk;

subplot(3,3,1)
plot(H(2))
subplot(3,3,2)
plot(H(3))
subplot(3,3,3)
plot(H(4))
subplot(3,3,5)
plot(H(7))
subplot(3,3,6)
plot(H(8))
subplot(3,3,9)
plot(H(9))

print -deps -mono p11c.eps

The function plotmatrix returns me a very nice plot of what I need - but I only need the upper right half of it. According to the docs, plotmatrix returns with H an array of plot handles, which can be plotted using plot .

However, executing this code results in 6 empty plots with weird axis, whereas the plotmatrix calls returns the correct plots.

What did I do wrong?

Answer 1

H represents the handles of the individual graphics objects, not the data (see documentation ). To do what you want, you need:

figure
subplot(3,3,1)
plot(get(H(2),'XData'),get(H(2),'YData'),'.')
subplot(3,3,2)
plot(get(H(3),'XData'),get(H(3),'YData'),'.')
subplot(3,3,3)
plot(get(H(4),'XData'),get(H(4),'YData'),'.')
subplot(3,3,5)
plot(get(H(7),'XData'),get(H(4),'YData'),'.')
subplot(3,3,6)
plot(get(H(8),'XData'),get(H(4),'YData'),'.')
subplot(3,3,9)
plot(get(H(9),'XData'),get(H(4),'YData'),'.')

BTW, I am not convinced that H is ordered the way you think it is. You might want to check that the data corresponds the bit of the matrix you are expecting.

Answer 2

This not really answer the question, but this code does what I needed:

for i = 1:3
    for j = i+1:4
        subplot (3, 3, (i-1)*3+(j-1));
        scatter (A(:,i), A(:,j));
    end
end