Changing color of point in stem plot based on value

I'm doing a stem plot of one vector in MATLAB. Can I change the color/marking of only the values that are zero in that vector? Right now, the 'points' of zero are only empty spaces in the stem plot.

Answer 1

[Matt Fig]

No, but that doesn't mean you can't get what you want.

t = (-3*pi:.1:3*pi);
y = round(sin(t)*5)/5;
idx = y~=0;
ynz = y(idx);
yz = y(~idx);
h = stem(t(idx),ynz,'fill','--');
hold on
h(2) = stem(t(~idx),yz);
set(get(h(1),'BaseLine'),'LineStyle',':')
set(h(1),'MarkerFaceColor','red')
set(h(2),'MarkerFaceColor','k','Markersize',8)

[M Brown]

Okay great- that's what I want it to look like but how would I do it if the data I plot is just a l by x matrix of numerical values

[Matt Fig]

In the case of a matrix instead of a vector (didn't you say in your OP that you had a vector??), each column is plotted separately. So do:

t = (-3*pi:.1:3*pi).';

y(:,1) = round(sin(t)*5)/5; % A matrix used for the call to STEM.

y(:,2) = round(cos(t)*5)/5;

idx = y~=0;

ynz = y;

ynz(~idx) = nan;

y(idx) = nan;

h{1} = stem(ynz,'fill','--');

hold on

h{2} = stem(y);

set(get(h{1}(1),'BaseLine'),'LineStyle',':')

set(h{1}(1),'MarkerFaceColor','red')

set(h{2}(1),'MarkerFaceColor','c','Markersize',10)

[M Brown]

Thank you!!!!