MATLAB: How to plot a graph where point colour relies on its value, based on several greater than and less than rules

plotplotting

I am trying to plot graphs where the points against the Y-axis determine the point itself to be one of five or more colours based on rules such as <0, >0 & <5, >5 & <42 etc.

Best Answer

Here's one way:

y = 10*rand(1, 150);
myColorMap = zeros(length(y), 3);
for k = 1 : length(y)
  if y(k) < 3
    myColorMap(k, :) = [1,0,0]; % Red
  elseif y(k) < 6
    myColorMap(k, :) = [1,0,1]; % Magenta
  else
    myColorMap(k, :) = [0,0,1]; % Blue
  end
end
x = 1:length(y);
scatter(x, y, 20, myColorMap, 'filled');
grid on;

Related Solutions

MATLAB: Marking a points in a curve that match condition

Try this:

numPoints = 20;
offset = 0.05; % How much away from the marker the text should be.
x = sort(rand(1, numPoints));
y = 10 * rand(1, numPoints);
plot(x, y, 'g', 'LineWidth', 2);
hold on;
index = (5 < y & y < 7);
plot(x(index), y(index), 'or', 'LineWidth', 2);
grid on;
for k = 1 : length(y)
  if index(k)
    caption = sprintf('x=%.2f, y=%.2f', x(k), y(k));
    text(x(k) + offset, y(k) + offset, caption, 'BackgroundColor', 'y');
  end
end

MATLAB: Greater than and less than

 if data(4) > 13 & data(4) < 15
      blah blah
 elseif data(4) > 2 & data(4) < 4
      other blah blah
 else
      that other thing
 end

Best Answer

Related Solutions

MATLAB: Marking a points in a curve that match condition

MATLAB: Greater than and less than

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