Matlab数据处理之移动最大值函数movmax

>> help movmax
 movmax   Moving maximum value.
    Y = movmax(X,K) for a vector X and positive integer scalar K computes a
    centered moving maximum by sliding a window of length K along X. Each
    element of Y is the local maximum of the corresponding values of X
    inside the window, with Y the same size as X. When K is even, the
    window is centered about the current and previous elements of X. The
    sliding window is truncated at the endpoints where there are fewer than
    K elements from X to fill the window.
    
    For N-D arrays, movmax operates along the first array dimension whose
    size does not equal 1.
 
    Y = movmax(X,[NB NF]) for a vector X and nonnegative integers NB and NF
    computes a moving maximum along the length of X, returning the local
    maximum of the previous NB elements, the current element, and the next
    NF elements of X.
 
    Y = movmax(...,DIM) operates along dimension DIM of X.
 
    movmax(...,MISSING) specifies how NaN (Not-a-Number) values are treated
    and can be one of the following:
 
        'omitnan'      - (default) the maximum of any window containing NaN
                         values is the maximum of all its non-NaN elements.
                         If all elements are NaN, the result is NaN.
        'includenan'   - the maximum of any window containing NaN values is
                         also NaN.
 
    movmax(...,'Endpoints',ENDPT) controls how the maximum is calculated at
    the endpoints of X, where there are not enough elements to fill the
    window. ENDPT can be either a scalar numeric or logical value or one of
    the following:
 
        'shrink'    - (default) compute the maximum over the number of
                      elements of X that are inside the window, effectively
                      reducing the window size to fit X at the endpoints.
        'fill'      - compute the maximum over the full window size,
                      filling missing values from X with -Inf. This is
                      equivalent to padding X with -Inf at the endpoints.
        'discard'   - compute the maximum only when the window is filled
                      with elements of X, discarding partial endpoint
                      calculations and their corresponding elements in Y.
                      This truncates the output; for a vector X and window
                      length K, Y has length LENGTH(X)-K+1.
                      
    When ENDPT is a scalar numeric or logical value, the missing elements
    of X inside the window are replaced with that value and Y remains the
    same size as X.
 
    Example: Compute a 5-point centered moving maximum.
        t = 1:10;
        x = [4 3 1 -2 -4 -1 0 2 -2 3];
        yc = movmax(x,5);
        plot(t,x,t,yc);
 
    Example: Compute a 5-point trailing moving maximum.
        t = 1:10;
        x = [4 3 1 -2 -4 -1 0 2 -2 3];
        yt = movmax(x,[4 0]);
        plot(t,x,t,yt);
 
    Example: Compute a 5-point centered moving maximum, padding the ends of
    the input with -Inf.
        t = 1:10;
        x = [4 3 1 -2 -4 -1 0 2 -2 3];
        yp = movmax(x,5,'Endpoints','fill');
        plot(t,x,t,yp);
 
    Example: Compute a 5-point trailing moving maximum, ignoring the first
    4 window shifts that do not contain 5 input elements.
        x = [4 3 1 -2 -4 -1 0 2 -2 3];
        yd = movmax(x,[4 0],'Endpoints','discard');

M = movmax(A,k)
M = movmax(A,[kb kf])
M = movmax(___,dim)
M = movmax(___,nanflag)
M = movmax(___,Name,Value)

>> A = [4 8 6 -1 -2 -3 -1 3 4 5];
>> M = movmax(A,3)

M =

     8     8     8     6    -1    -1     3     4     5     5

>> A = [4 8 6 -1 -2 -3 -1 3 4 5];
>> M = movmax(A,[2 0])

M =

     4     8     8     8     6    -1    -1     3     4     5

>> A = [4 8 6; -1 -2 -3; -1 3 4]

A =

     4     8     6
    -1    -2    -3
    -1     3     4

>> M = movmax(A,3,2)

M =

     8     8     8
    -1    -1    -2
     3     4     4

>> A = [4 8 NaN -1 -2 -3 NaN 3 4 5];
>> M = movmax(A,3)

M =

     8     8     8    -1    -1    -2     3     4     5     5

>> M = movmax(A,3,'includenan')

M =

     8   NaN   NaN   NaN    -1   NaN   NaN   NaN     5     5

>> A = [4 8 6 -1 -2 -3];
>> k = hours(3);
>> t = datetime(2016,1,1,0,0,0) + hours(0:5)

t = 

1 至 5 列

   2016-01-01 00:00:00   2016-01-01 01:00:00   2016-01-01 02:00:00   2016-01-01 03:00:00   2016-01-01 04:00:00

6 列

   2016-01-01 05:00:00

>> M = movmax(A,k,'SamplePoints',t)
错误使用 movmax
窗口长度必须为有限标量正整数，或者为包含有限非负整数的 2 元矢量。

>> M = movmax(A,k,'SamplePoints',t)

M = 1×6

     8     8     8     6    -1    -2

>> A = [4 8 6 -1 -2 -3 -1 3 4 5];
>> M = movmax(A,3,'Endpoints','discard')

M =

     8     8     6    -1    -1     3     4     5