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dim_cumsum_n_Wrap

Calculates the cumulative sum along the given dimension(s) and retains metadata.

Available in version 5.1.1 and later.

Prototype

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"

	function dim_cumsum_n_Wrap (
		x        : numeric,  
		opt      : integer,  
		dims [*] : integer   
	)

	return_val [dimsizes(x)] :  float or double

Arguments

x

A variable of numeric type and any dimensionality.

opt

Option for how to treat _FillValue:

  • opt = 0 ; when _FillValue is encountered no additional summing will be performed.
  • opt = 1 ; when _FillValue is encountered set element to _FillValue and resume summing
  • opt = 2 ; treat _FillValue as numeric zero when summing

dims

The dimension(s) of x on which to do the cumulative sum across.

Return value

The same type and dimensionality as x.

Description

This function calculates the cumulative sum of all elements of dimensions indicated by dims for each index of the remaining dimensions. A wrapper function. Missing values are treated differently as specified by opt

See Also

dim_acumrun_n, dim_cumsum_Wrap, dim_cumsum, dim_cumsum_n, cumsum, dim_cumsum, dim_rmvmean, dim_rmvmed

Examples

Example 1: When no _FillValue are encountered all three options return the same result.

  x        = (/1,2,3,4,5/)
  x_sum    = sum(x)            ; result 15        
  x_cumsum = dim_cumsum_n_Wrap(x, 0, 0)  ; result (/1  3  6  10  15/)
  x_cumsum = dim_cumsum_n_Wrap(x, 1, 0)  ; result (/1  3  6  10  15/)
  x_cumsum = dim_cumsum_n_Wrap(x, 2, 0)  ; result (/1  3  6  10  15/)
Note: for a 1D array, it is simpler to use dim_cumsum_Wrap.

Example 2: When one or more _FillValue are encountered, each option yields a different answer.

  x        = (/1,2,-999,4,5/)
  x@_FillValue = -999 
  x_sum    = sum(x)            ; result 12
  x_cumsum = dim_cumsum_n_Wrap(x, 0, 0)  ; result (/1  3 -999 -999 -999/)
  x_cumsum = dim_cumsum_n_Wrap(x, 1, 0)  ; result (/1  3 -999    7   12/)
  x_cumsum = dim_cumsum_n_Wrap(x, 2, 0)  ; result (/1  3    3    7   12/)
Example 3: Let p(time,lat,lon) and calculate cumulative sums at each time. The opt argument can be set by the user.
  p_cumsum = dim_cumsum_n_Wrap(p,opt,0)