Custom colors on plots

Hi, i'm trying to plot:

x=[1,2,3,4,5,6,7,8,9];
y=[9,8,7,6,5,4,3,2,1];

which gives me a straight line,

I also have a third array

height=[0,0,2,3,0,0,2,1,0];

I want to plot markers on the plot above whenever height(i) is not equal to 0.

I can do this by using:

plot(xVal,yVal,'ks','markerfacecolor',[0 0 0]);

however this only works for black/default colours. I want to be able to have different shades of blue for each marker depending on how large height(i) is for each point.

How can I get custom colors?

Answer 1

[Image Analyst]

You can plot them one at a time:

x=[1,2,3,4,5,6,7,8,9];
y=[9,8,7,6,5,4,3,2,1];

height=[0,0,2,3,0,0,2,1,0];
heightDifferences = abs(height - y);
% Find the max height difference.
% This will be put blue.  Others will be less blue.
% I.e., on line = black, furthest away = pure blue.
maxHeightDiff = max(heightDifferences(height~=0));
plot(x,y,'ks','markerfacecolor',[0 0 0]);
plot(x,y,'rd-');
grid on;
hold on;
for k = 1 : length(height)
  if height(k) ~= 0
    theColor = [0,0,heightDifferences(k)/maxHeightDiff];
    plot(x(k), height(k), 'o', 'markerfacecolor', theColor,...
      'MarkerSize', 15);
  end
end

Or you can call scatter() and pass in the colors if you make theColor an array in the above code.