Matlab快速入门之帮助和文档

Matlab内置大量函数，那么我们该如何使用这些函数呢。有时候，我们不知道该如何使用函数，比如函数的输入参数和输出参数是怎么样的。这个问题，其实Matlab早就想到了。于是，Matlab还内置了这些函数的帮助说明以及文档说明。

所有 MATLAB^® 函数都有辅助文档，这些文档包含一些示例，并介绍函数输入、输出和调用语法。从命令行访问此信息有多种方法：下面我们以函数mean来讲解如何获取帮助和文档。

使用 doc 命令在单独的窗口中打开函数文档。

doc mean

这时，Matlab会弹出一个文档页面，里面会给出mean函数的使用方法，并且会给出几个例子说明。

在键入函数输入参数的左括号之后暂停，此时命令行窗口中会显示相应函数的提示（函数文档的语法部分）。

mean(

使用 help 命令可在命令行窗口中查看相应函数的简明文档。

>> help mean
 mean   Average or mean value.
    S = mean(X) is the mean value of the elements in X if X is a vector. 
    For matrices, S is a row vector containing the mean value of each 
    column. 
    For N-D arrays, S is the mean value of the elements along the first 
    array dimension whose size does not equal 1.
 
    mean(X,DIM) takes the mean along the dimension DIM of X.
 
    S = mean(..., TYPE) specifies the type in which the mean is performed, 
    and the type of S. Available options are:
 
    'double'    -  S has class double for any input X
    'native'    -  S has the same class as X
    'default'   -  If X is floating point, that is double or single,
                   S has the same class as X. If X is not floating point, 
                   S has class double.
 
    S = mean(..., MISSING) specifies how NaN (Not-A-Number) values are 
    treated. The default is 'includenan':
 
    'includenan' - the mean of a vector containing NaN values is also NaN.
    'omitnan'    - the mean of a vector containing NaN values is the mean 
                   of all its non-NaN elements. If all elements are NaN,
                   the result is NaN.
 
    Example: If X = [1 2 3; 3 3 6; 4 6 8; 4 7 7];
 
    then mean(X,1) is [3 4.5 6] and mean(X,2) is [2; 4; 6; 6]
 
    Class support for input X:
       float: double, single
       integer: uint8, int8, uint16, int16, uint32,
                int32, uint64, int64