How to display only few values in a plot rather than for whole points in a big array?

i have to plot a graph for a variable T which is dependent on two variables x and t with x and T as x and y axes respectively at some specific values of t. I have written the following code for that:

y=0.01;

t=y:10*y:1000*y; % t=time (hr)

x=0:0.001:1;

for l=1:length(x)

for k=1:length(t)

a=60*sqrt(4*alpha*t(k));

b=a/sqrt(pi);

c=qs/K;

d=exp(-(x(l)/a).^2);

T(l,k)=c*(b*d-x(l).*erfc(x(l)/a))+Ti;

end

end

ts=t(:,4);

plot(x,T);

when I'm running it the graph is plotting for all the values of t in the array which makes the plot a solid like display. I have to plot for some 8 to 10 values of t only please help!!!!!!!!!

Answer 1

[Karim]

See below for a demonstration, i had to assume some parameters. However the plotting princaple remains the same.

% these parameters were missing from the OP's question, hence assumed to be 1
alpha = 1;
qs = 1;
K = 1;
Ti = 1;

% parameters from the OP's question
y = 0.01;
t = y:10*y:1000*y;
x = 0:0.001:1; 

% initialize matrix T
T = zeros(length(x),length(t));

for l = 1:length(x)
    for k = 1:length(t)
        a = 60*sqrt(4*alpha*t(k));
        b = a/sqrt(pi);
        c = qs/K;
        d = exp(-(x(l)./a).^2);
        T(l,k) = c*(b*d-x(l).*erfc(x(l)./a))+Ti;
    end
end
ts = t(:,4);

% make the full plot
figure
plot(x,T)
grid on

%% only plot some selected 't' values

% first pick a few t values
T_pick = [1 5 10 20 50 75 100];

% in the plot command, use the 2nd dimension to plot the selected values
figure
plot(x, T(:,T_pick))
grid on

[RITU SRIVASTAVA]

Thankyou sir, its working....

Answer 2

[Davide Masiello]

n = 10;
plot(x,T(:,1:n:end));

By increasing the value of n you decrease the number of lines shown in your plot.

[RITU SRIVASTAVA]

Thankyou sir, its working well.