How to color a specific value ?

%Sine and cos sequence in MATLAB
close all;
clc;
n=-20:20;
x_n=sin(pi/2-2*pi*0.1*n);
plot(n,x_n);
xlabel('Time sample');
ylabel('Amplitude');
hold on;
x2_n=cos(2*pi*0.1*n);
plot(n,x_n);
xlabel('Time sample');
ylabel('Amplitude');

very good moring to all of you.

can anyone help me I want to color positive value in a red and negative value in blue??

[Jiri Hajek]

Hi, see this discussion with examples: https://stackoverflow.com/questions/31685078/change-color-of-2d-plot-line-depending-on-3rd-value

[Abubakr Mursi]

Hi,

all i need to color peak and trough values with a color by utilizing (area)

Answer 1

[daniel mitchell]

%Sine and cos sequence in MATLAB
close all;
clc;
n=-20:20;
f = 0.1;
n0 =  1/(4*f)-4/(2*f):1/(2*f):1/(4*f)+3/(2*f);
ns = sort([n n0]);

x_n=sin(pi/2-2*pi*0.1*ns);
x_n = round(x_n,3);
x_n_neg = nan(size(x_n)); x_n_neg(x_n<=0) = x_n(x_n<=0);
x_n_pos = nan(size(x_n)); x_n_pos(x_n>=0) = x_n(x_n>=0);
figure; hold on;
plot(ns,x_n_neg,'r');
plot(ns,x_n_pos,'b');
xlabel('Time sample');
ylabel('Amplitude');

[Abubakr Mursi]

i need to fill it each value with a color by using area fuction to plot it

[daniel mitchell]

just noticced it now well simply replace plot with area..

%Sine and cos sequence in MATLAB
close all;
clc;
n=-20:20;
f = 0.1;
n0 =  1/(4*f)-4/(2*f):1/(2*f):1/(4*f)+3/(2*f);
ns = sort([n n0]);
x_n=sin(pi/2-2*pi*0.1*ns);
x_n = round(x_n,3);
x_n_neg = nan(size(x_n)); x_n_neg(x_n<=0) = x_n(x_n<=0);
x_n_pos = nan(size(x_n)); x_n_pos(x_n>=0) = x_n(x_n>=0);
figure; hold on;
area(ns,x_n_neg);
area(ns,x_n_pos);
xlabel('Time sample');
ylabel('Amplitude');

[Abubakr Mursi]

Thanks Deeply @daniel mitchell