Saturday, April 25, 2009

Simple graphs - 4

Let's continue our study about the plot(.) function.

Now, how change the graph's color?

The plot(.) has a argument that's a string.

We can do:

  • plot(x, y, color);
  • plot(y, color);
Remember, when the x vector isn't in the function, the default is [1:length(y)], where length(y) is the number of elements that y vector has.

The possible colors are:

  • red ("r");
  • green ("g");
  • blue ("b");
  • cyan ("c");
  • magenta ("m");
  • yellow ("y");
  • black ("k");
  • white ("w").

Let's do an example:

-->x = [-100:100]';

-->y1 = abs(x.^3)/1e+5;

-->y2 = x.^3 + x.^2 + 1;

-->y3 = tanh(0.01*x);

-->y2 = y2/max(y2);

-->plot(x, y1);

-->plot(x, y2, "r");

-->plot(x, y3, "g");

-->scf(); plot(x, y2, "k"); plot(x, y3, "y");

This example uses some functions that I had written about, so review the blog if you don't understand anything, or comment here.

The result is following.

Look that the default color is blue.

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