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dim_rmvmed_n

Calculates and removes the median of the given dimension(s) at all other dimensions.

Prototype

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

	return_val [dimsizes(x)] :  float or double

Arguments

A variable of numeric type and any dimensionality.

dims

The dimension(s) of x on which to calculate and remove the median. Must be consecutive and monotonically increasing.

Return value

The output is of type double if the input is double, and float otherwise.

The dimensionality is the same as the input dimensionality.

Description

The dim_rmvmed_n function calculates and removes the median from all elements of the dimensions indicated by dims for each index of the remaining dimensions. Missing values are ignored.

Use the dim_rmvmed_n_Wrap function if metadata retention is desired. The interface is identical.

Examples

Example 1:

Let x be a 1-dimensional array: (a) Create a new variable, xNew, that contains just the deviations from the median; (b) replace the variable x with the deviations.

  xNew = dim_rmvmed_n(x,0)     ; new variable
  x    = dim_rmvmed_n(x,0)     ; overwrite with deviations

  ; Use dim_rmvmed_n_Wrap if metadata retention is desired
  ; xNew = dim_rmvmed_n_Wrap(x,0)     ; new variable
  ; x    = dim_rmvmed_n_Wrap(x,0)     ; overwrite with deviations

Note: when operating across the rightmost dimension, it is simpler to use dim_rmvmed.

Example 2:

Let x be a 3-dimensional array with dimension sizes (ntim, nlat, nlon). To remove the medians of the "nlon" dimension:

   xRmvLon = dim_rmvmed_n (x,2)       ; new variable containing deviations (no metadata)
   x       = dim_rmvmed_n (x,2)       ; overwrite with deviations from median

   ; Use dim_rmvmed_n_Wrap if metadata retention is desired
   ; xRmvLon = dim_rmvmed_n_Wrap (x,2)       ; new variable containing deviations
   ; x       = dim_rmvmed_n_Wrap (x,2)       ; overwrite with deviations from median

Example 3:

Let x be a 3-dimensional array with named dimensions (time, lat, lon) and dimension sizes (ntim, nlat, nlon). To remove the median of the time dimension from all lat/lon indices:

   xRmvTime = dim_rmvmed_n(x,0)

   ; Use dim_rmvmed_n_Wrap if metadata retention is desired
   ; xRmvTime = dim_rmvmed_n_Wrap(x,0)

Example 4:

Let x be a 4-dimensional array with named dimensions (time, lev, lat, lon) and dimension sizes (ntim, nlev, nlat, nlon). To remove the median of the time/lev dimensions from all lat/lon indices:

   xRmv = dim_rmvmed_n(x,(/0,1/))

   ; Use dim_rmvmed_n_Wrap if metadata retention is desired
   ; xRmv = dim_rmvmed_n_Wrap(x,(/0,1/))

Example 5:

Let x be as in Example 3 and let x contain monthly medians for (say) 10 years of data (ntim=120). Monthly anomalies for each month could be calculated using array subscripting.