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cumsum

Calculates the cumulative sum.

Prototype

	function cumsum (
		x    : numeric,  
		opt  : integer   
	)

	return_val [dimsizes(x)] :  typeof(x)

Arguments

x

A variable of numeric type and any dimensionality.

opt

Option for how to treat _FillValue.

  • opt = 0 ; when _FillValue is encountered, set current element and all remaining to _FillValue.
  • opt = 1 ; when _FillValue is encountered set element to _FillValue and resume summing.
  • opt = 2 ; treat _FillValue as numeric zero when summing.

Return value

The same type and dimensionality as x.

Description

The cumsum function calculates the cumulative sum of all elements. Missing values are treated differently as specified by opt.

See Also

dim_cumsum, dim_cumsum_Wrap, 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 = cumsum(x, 0)  ; result (/1  3  6  10  15/)
  x_cumsum = cumsum(x, 1)  ; result (/1  3  6  10  15/)
  x_cumsum = cumsum(x, 2)  ; result (/1  3  6  10  15/)
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 = cumsum(x, 0)  ; result (/1  3 -999 -999 -999/)
  x_cumsum = cumsum(x, 1)  ; result (/1  3 -999    7   12/)
  x_cumsum = cumsum(x, 2)  ; result (/1  3    3    7   12/)