MatLab Handouts (4) --- MatLab Functions
MatLab graphing facilities: plot, subplot, title, text, axis


  1. MatLab function plot plots given ordered pairs (x(1),y(1)), (x(2),y(2)),..., where x(i) and y(i) are stored in vectors x and y. For example, copy and paste the following 4 commands in MatLab to see how plot works.
       x=[1;2;3;4];
       y=[-1;2;-3;4];
       plot(x,y,'--')
    
    '--' in plot is for the line-type. Other line types and point types are:
       line-type:  -, --, :, -.
       point-type: ., +, *, o, x
    
    Type help plot to learn more about plot.

  2. MatLab function subplot provides a location for a graph on a multigraphs screen. For example, subplot(3,2,4) means that the plotted graph is the 4th graph on a screen which has 6 graphs (in 3 rows and 2 columns). Try the following commands to see how subplot works.
       x=[1;2;3;4];
       y=[-1;2;-3;4];
       subplot(3,2,4),plot(x,y,'--')
    
    Type help subplot to learn more about subplot.

  3. MatLab function axis provides limits of x-axis and y-axis. For example,
       subplot(3,2,4),axis([-5 5 -6 6])
       subplot(3,2,4),axis square
    
    x is in [-5 5] and y is in [-6 6] and then the graph window becomes a square window. Type help axis to learn more about axis.

  4. MatLab function title displays a given title in text. For example,
       title('It is a test.')
    
    the title will be above the graph window.

  5. MatLab function text allows us to add text to the graph. For example,
       text(1,2,'It is a test.')
    
    the text will be added at the location (1,2).

  6. MatLab function clg (for MatLab version 4) and clf (for MatLab version 5) cleans the screen. Type help clg or help clf to learn more about these two comments.