help, by itself, lists all primary help topics. Each main help topic corresponds to a directory name on MATLAB's search path.
topic gives help on the specified topic. The topic can be a function name or a directory name. If it is a function name,
help displays information on that function. If it is a directory name,
help displays the contents file for the specified directory. It is not necessary to give the full pathname of the directory; the last component, or the last several components, is sufficient.
You can write help text for your own M-files and toolboxes; see the following sections for more information.
help, by itself, lists all help topics by displaying the first line (the H1 line) of the contents files in each directory on MATLAB's
Contents.m within each directory.
topic is a directory name, displays the comment lines in the
Contents.m file located in that directory. If a contents file does not exist,
help displays the H1 lines of all the files in the directory.
topic is a function name, displays help on the function by listing the first comment lines in the M-file
angle.mprovided with MATLAB contains:
When you execute
function p = angle(h)
% ANGLE Polar angle.
% ANGLE(H) returns the phase angles, in radians, of a matrix
% with complex elements. Use ABS for the magnitudes.
p = atan2(imag(h),real(h));
help angle, lines 2, 3, and 4 display. These lines are the first block of contiguous comment lines. The help system ignores comment lines that appear later in an M-file, after any executable statements, or after a blank line.
The first comment line in any M-file (the H1 line) is special. It contains the function name and a succinct description of the function. The
lookfor command searches and displays this line, and
help displays these lines in directories that do not contain a
Contents.mfile is provided for each M-file directory included with the MATLAB software. If you create directories in which to store your own M-files, you can create
Contents.mfiles for them too. To do so, simply follow the format used in an existing
To prevent long descriptions from scrolling off the screen before you have time to read them, enter
on; then enter the
(c) Copyright 1994 by The MathWorks, Inc.