Plot different curves in cycle for

I want to plot 3 different curves in the same graph (one parameter changing).

if true
for M0=1.5:0.5:2.5
  disp('Valori scelti di Mi')
  Mi=0.4:0.05:0.7
[...]
  yyaxis left
  grid minor
  plot(Mi,Dad,'-^','LineWidth', 2,'MarkerSize',8);
  xlabel('Mi','FontSize',14)
  ylabel('Resistenza addizionale','FontSize',14)
  title('Resistenza addizionale presa Pitot subcritica','FontSize',16)
  yyaxis right
  plot(Mi,PhiD,'-*','LineWidth',2,'MarkerSize',8)
  ylabel('Coeff. di Portata','FontSize',14)
  hold on

(ignore the first line if true).

Wath I want is to get this graph with every blu and orange line with different style operating inside the for command.

Answer 1

[dbmn]

You where almost correct. Just 2 small corrections:

1) "hold on" You added this line at the end of the script - this wont help you. Think about hold on as only between the two lines hold on / hold off that function is active (even if you dont specify hold off) -> just add hold on earlier in your code

2) use plotyy instead of plot. This allows you to get plots with 2 y axes

3) try to use handles, f.ex. h1 = plot(...). This allows you to accees the plotted lines much easier later in your script

[Davide Bassignana]

What do you mean by insert hold on earlier in the code? I am trying to use a separate cycle for in order to change colours of the lines (I am thinking at a vector containing the sequence of colours to be used, I know matlab already does this but in this case it doesen't work probably because I used yyaxis...)

[dbmn]

This should do what your picture does. I took the title and labels out of the loop.

if true

    figure; % create handle to figure
    hold on
    title('Resistenza addizionale presa Pitot subcritica','FontSize',16)
    grid minor
    xlabel('Mi','FontSize',14)
    yyaxis left
    ylabel('Resistenza addizionale','FontSize',14)
    yyaxis right
    ylabel('Coeff. di Portata','FontSize',14)
 % Foor Loop
    for M0=1.5:0.5:2.5
      disp('Valori scelti di Mi')
      Mi=0.4:0.05:0.7
      Dad = rand(size(Mi));
      PhiD = rand(size(Mi));
      % Plot left thingy
      yyaxis left
      plot(Mi,Dad,'-^','LineWidth', 2,'MarkerSize',8);
      % Plot right things
      yyaxis right
      plot(Mi,PhiD,'-*','LineWidth',2,'MarkerSize',8)
    end
end

If you want changing Line styles you could define a variable such as (before the for loop)

my_linestyle = {'-^','-*','-o'};
i = 0;

and access this in the loop as follows

i = i+1;
plot(Mi,Dad,'linestyle',my_linestyle{i},'LineWidth', 2,'MarkerSize',8);

[dbmn]

ooops. Correction - i was to fast. Now it should work :) (tested)

plot(Mi,Dad,my_linestyle{i},'LineWidth', 2,'MarkerSize',8);