How to change the color of a graph only in a particular section?

Hey all,

I was just wondering if there is a way to change a particular part of a plot to another color? Suppose we have a plotted signal in BLUE and we wannan show the main response (let's say with the highest amplitude) in RED.

Answer 1

[Jan]

You can draw different lines.

t = 0:0.02:4*pi;
y = sin(t);
index = (y >= 0);
plot(t, y, 'b');
plot(t(index), y(index), 'r');

[Matt Tearle]

A nice trick to remove points graphically is to set them to NaN. Eg

t = 0:0.02:4*pi;

y = sin(t);

z1 = y;

z1(y>=0) = NaN;

z2 = y;

z2(y<0) = NaN;

plot(t,z1,'b',t,z2,'r')

And while I'm here, I might as well peddle my wares: http://www.mathworks.com/matlabcentral/fileexchange/30423-conditionally-colored-line-plot

Answer 2

[Korosh Agha Mohammad Ghasemi]

%https://zil.ink/korosh                       -------- Ways to contact me ----------
% Korosh Agha Mohammad Ghasemi !
%  Chemical Engineering at Shiraz University
x=linspace(0,2,100);
figure;
for a=[0.1 0.5 1 2 4]
y=x.^a;     %The function is hypothetical
if a == 0.1    %Any color can be substituted
    y=x.^a;
    plot(x,y,'k')  %Now choose the color
    hold on
elseif a == 0.5
    y=x.^a;
    plot(x,y,'b')   %Now choose the color
    hold on
elseif  a==1
    y=x.^a;
    plot(x,y,'g')    %Now choose the color
    hold on
elseif a==2
    y=x.^a;
    plot(x,y,'r')   %Now choose the color
    hold on
elseif a==4
    y=x.^a;
    plot(x,y,'y')   %Now choose the color
hold on
grid on
end
end