Example script for a simple single plot of a function

AH 2010.1.29


Plot parameters

xStart = -1;        % starting x value
xEnd = 1;           % ending x value
nPoints = 200;      % number of points in plot

The function to plot

For this example, the function is called 'squareFn' and is defined in a separate file called squareFn.m.

Make x and y data vectors

x = linspace(xStart, xEnd, nPoints);   % independent variable vector
y = squareFn(x);                       % dependent variable

Make the plot, adding labels and a title

clf                         % clear the figure area, just in case
hold on                     % lock the plot to be able to add other parts
plot(x, y, 'b')             % plot y vs. x, with blue line
xlabel('x variable')        % x label
ylabel('y variable')        % y label
title('Plot of squareFn')   % title for plot
    % add other elements to the plot here...
hold off                    % unlock plot

Adding more curves, points, and so on...

The 'hold on' and 'hold off' lines above aren't necessary for this simple example, but are necessary to add more lines and so on to an existing plot. For instance, to add green crosses at points at x-coordinates w and y-coordinates z, add the command plot(w, z, 'g+') between the two holds. Use the help page for 'plot' to find options for points, lines, etc.