MATLAB: How to color individual lines in a plot

Question

Hello all,

I'm a novice user and I'm attempting to use something like "colormap jet" on a plot so that each line within the plot is a different color. The x-axis is temperature and the y-axis is depth. Each line is at a temperature, so I'd like the colors to make the graph easier to read (e.g. colder to hotter).

I haven't found a solution on here that works so far. I think it might have to do with how the data are plotted.

Here's the code:

dates = datevec(datetime); %set matlab dates to year,month,day,hour,min,sec
dates = dates'; %invert
temp_crop = calTemp(387:417,:); %only interested in temps along this length of cable
ind_midnight = find(dates(4,:)==0); %finding all temp measures along cable where hour is 0 (midnight)
ind_noon = find(dates(4,:)==12); %same as above, but with noon

midnighttemps = temp_crop(:,ind_midnight); %have all temps along cropped section of cable for each day at midnight
noontemps = temp_crop(:,ind_noon); %same as above, but with noon
close all
figure; 
subplot(1,2,1);
plot(midnighttemps);
view([90 -90]);
title('midnight');
subplot(1,2,2);
plot(noontemps);
view([90 -90]);
title('noon');

You can see how the plot is actually plotting individual matrices with a single column. I think this might be why I can't do a simple colormap or colorbar. I've also tried a few for loops such as this:

x = [0:0.1:10];
linecolors = jet(5);
for i=1:5
    plot(x,x.^(i/3),'color',linecolors(i,:));
    hold on;
end 

I found this on StackOverflow, and the graph it produces is what I'd like, individually colored lines on a gradient, but I can't seem to get it to work. Again, I think this is because I'm plotting an entire matrix. Any suggestions?

Thank you for any assistance.

Answer 1

You can change the default color order to do exactly what you want. In fact I already have a demo that does it. See attached m-file.