Choose automatic use of colour in plot

hey guys, I have a problem with the plot instruction. Usually, when I type

    figure
    hold on
    plot(x_1,y_1)
    plot(x_2,y_2)

I will get a plot with two lines in different colors. I don't know what happend but it's not running with my Matlab version scince a few weeks. I'm using Matlab R2014a. When I type this code I get a plot with two lines and both lines are blue. I know that I can choose the colour in the plot enviroment with

    plot(x_1,y_1,'r')

but I want that the color's chosen automatically.

Is there anyone who has an idea what I can do?

Answer 1

[Walter Roberson]

This is a difference that came in from R2014b onwards. The R2014a and earlier equivalent is

hold all

Answer 2

[Shih-Hsuan Yuan]

I can think of 2 ways to help you.

1.

plot(x_1,y_1,x_2,y_2);

Simplest way.

2. https://www.mathworks.com/matlabcentral/fileexchange/29702-generate-maximally-perceptually-distinct-colors/content/distinguishable_colors.m

Or if you want some sort of controls over the color. You can download this function. Basically this function generate random distinguishable colors for you.

color_data = distinguishable_colors(2);
plot(x_1,y_1,color_data(1,:);
plot(x_2,y_2,color_data(2,:);

Or you can use to colormap function in MATLAB. It will do similar thing for you.