MATLAB HINTS - HOMEWORK 0
M. Nelson  Spring 2004

New Matlab Commands

(to get more info, type 'help <cmd>' at the matlab prompt)
`axis`
axis([xmin xmax ymin ymax]) sets scaling for the x- and y-axes
`clear`
removes all variables from the workspace
`clf`
clears the current figure
`figure`
figure by itself, creates a new figure window
figure(N)  makes N the current figure, when N is an integer
if figure N does not already exist a new figure is created
`grid`
grid on adds major grid lines to the current axes.
grid off  removes major and minor grid lines from the current axes.
hold
hold on  holds the current plot and all axis properties so that
subsequent plot commands add to the existing graph.

hold off  returns to the default mode whereby plot commands erase
the previous plots and reset all axis properties before drawing
orient
orient is used to set up the orientation of a figure for printing

orient landscape causes subsequent print operations to generate
output in full-page landscape orientation on the paper.
orient portrait --  portrait orientation, wide margins
orient tall -- portrait orientation, uses full page
`plot`
plot(x, y)  plots vector y versus vector x.
plot(y)  plots the vector y versus it's index.

Various line types, plot symbols and colors may be obtained with
plot(x, y, 'str') where 'str'  is a character string made from one element
from any or all the following 3 columns:

 Color Plot Symbol Line Style r     red .     point -     solid g     green o     circle :     dotted b     blue x     x-mark -.    dashdot c     cyan +     plus --    dashed m     magenta *     star y     yellow s     square k     black d     diamond v     triangle (down) ^     triangle (up) <     triangle (left) >     triangle (right) p     pentagram h     hexagram

For example:
plot(x,y,'c-') plots a cyan line without any plot symbols
plot(x,y,'rx--')  plots red  x at each data point  joined with a dashed line
plot(x,y,  'ko') plots black circles at each data point without any line
`subplot`
subplot(m,n,p) breaks the figure window into an m-by-n grid of axes,
and selects the p-th axes for for the current plot..  The axes are counted along the top row of the igure window, then the second row, etc.
Example: subplot(2,2,1) divides the page into a 2x2 grid and selects the upper left corner (p=1) for the current plot.
`title`
title('text') adds 'text' at the top of the current axis.
`xlabel`
xlabel('text') adds 'text' below the X-axis on the current axis.
`ylabel`
ylabel('text') adds 'text' beside the Y-axis on the current axis.

Example Script
(you can copy-and-paste this into the matlab command window or save it as an m-file)
 clear; figure(1); clf; t = 0 : 0.02 : 1.0; y1 = sin(2*pi*t); y2 = cos(2*pi*3*t); subplot(2,1,1); plot(t, y1, 'ro-'); hold on; plot(t, y2, 'b--'); title('This is the title'); ylabel('voltage (mV)'); axis([0 1 -1.5 1.5]); subplot(2,1,2) plot(t, y1+y2, 'm:'); axis([0 1 -3 3]); grid on xlabel('time (sec)'); ylabel('voltage (mV)'); orient landscape;
`  `