Changing colors in scatter plots?

Greetings all,

I was trying to somehow change colors of a scatter plot I have of two values.

What I started off with was this:

   scatter(ModelFile(:,4), z_i_1_abs)

where the "x" value - ModelFile(:,4) has 1156x1 values, and the same for the "y" value - z_i_1_abs - it also has 1156x1 values. This line plots succesfully, but I want ModelFile(:,4) to be one color and z_i_1_abs to be a separate color. When I plot it now, both are blue.

So I looked at gscatter and the good old plot command, and I tried hold on, but I just keep getting errors.

Any advice?

Thanks!

     -J

[Image Analyst]

I don't understand. It's a scatter plot - it's not like you have two different sets of data where you can plot each with a certain color against some independent x axis. Your array ModelFile DEFINES the x axis. You have the kth point at (x,y) where x=ModelFile(k,4) and y = z_i_1_abs(k). What's to distinguish one set from the other?

[Jesse]

Walter,

Sorry getting back to this so late, but I never received an email stating that my post was updated.

Ok, I see what your saying now, and I just thought that your array values in the first position (or x) could have different colors since the "y" values is another column of data. That's all I was checking.

I was looking at something on the web and I thought that this could be accomplished - apparently not.

[Jiro Doke]

Right. You can't have 2 colors for a single point. You can't even do that with a paper and a colored pencil. Unless you're saying you want half of the circle to be one color and the other half of the circle to be another. But I doubt that's what you want.

[Walter Roberson]

By the way: Image Analyst's name is not "Walter".

[Jesse]

Ok, apologies for the confusion about the names. Honestly I saw your name Walter, but Image Analyst's was the only comment that appeared - not yours, so I mistakenly thought you were two of the same people.

To all the others, thanks for the feedback, but hey I'm no expert at MATLAB. I just thought I could have one column in one color and the other column in another color, that's all. No need to persecute someone for learning.

Answer 1

[Walter Roberson]

I'm not sure what you think you want, but perhaps:

dotsize = 10;
n = length(z_i_1_abs);
scatter( 1:n, ModelFile(:,4), dotsize, 'b');
hold on
scatter( 1:n, z_i_1_abs, dotsize, 'r');

[Jesse]

Yes that's what I was looking for - thank you.

[Walter Roberson]

We wouldn't normally think of that as a scatter plot.

Another way of accomplishing the same thing would be:

plot( [ModelFile(:,4), z_i_1_abs(:)], 'o')

This can be extended to any number of columns, but each column must be the same size. (Also, colors would start to repeat after the 8th column.)

[Jesse]

Cool - thanks for all of the insight! I appreciate it.