Plot Multiple Colours automatically in a for loop

Hi,

I am trying to plot a graph, with a different colour being used automatically for each line on the plot, is there a simple way to do this? Here is my code:

% Define a range of y values
y = [0:0.01:1];

hold on

% Create a loop, which calculates the velocity profile for each a_0
% coefficient in the range 0 => 2.67 with 0.267 increments:
for a_0 = [0:0.267:2.67];

      for i = 1:length(y)

          % Define boundary layer thickness delta as 99% U_inf
          delta = 0.99;
          % Define eta as a function of y position and the constant delta:
          eta(i) = y(i)./delta;
          % Calculate the velocity profile:
          u_prof(i) = (a_0.*eta(i)) - ((((3./2).*a_0)-2).*(eta(i).^2)) - ((1- (a_0./2)).*(eta(i).^4));

      end
      % Plot the velocity profile for each a_0 coefficient
      plot (u_prof,y)
      grid on

end

hold off

Thanks,

Robbie

Answer 1

[Chandra Kurniawan]

You should replace line

plot (u_prof,y)

with

plot (u_prof,y,'color',rand(1,3))

[Robbie]

Thanks Chndra, that is just what I was looking for

[Rajan Kumar]

Why (1,3) can it be any other number?

[Ilham Hardy]

No it can't.

To resembles the rgb input (1x3 matrix)

Answer 2

[C.J. Harris]

I would suggest taking a look at the 'hold all' command. Just replace the line:

hold on

with:

hold all

That way you won't have to make any other modifications to your code.

[Robbie]

Thanks Chris, that is useful

[Dili Sam]

THANKS IT WAS USEFUL FOR ME TOO... SAVED MY TIME!!

[Taha Alian]

Excelent

Answer 3

[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