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latRegWgt

Generates [sin(lat+dlat/2)-sin(lat-dlat/2)] weights for equally spaced (regular) global grids that will sum to 2.0.

Available in version 5.1.0 and later.

Prototype

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"  ; This library is automatically loaded
                                                             ; from NCL V6.2.0 onward.
                                                             ; No need for user to explicitly load.

	function latRegWgt (
		lat   [*] : numeric,  
		nType [1] : string,   
		opt   [1] : integer   
	)

	return_val [*] :  float

Arguments

lat

Latitudes of global grid [degrees].

nType

Type of variable to be returned [float or double].

opt

Not used. Set to 0.

Return value

A one-dimensional array of same size as lat.

Description

Generates [sin(lat+dlat/2)-sin(lat-dlat/2)] for global grids. The weights will sum to 2.

See Also

latGauWgt, NormCosWgtGlobe, latGau, latGlobeF, latGlobeFo, lonGlobeF, lonGlobeFo, gaus

Examples

Example 1

Consider a variable lat that spans 87.5S to 87.5N [5 deg spacing]. 

  wgt  = latRegWgt(lat, "double", 0)

  printVarSummary(wgt)
  print(lat+"    "+wgt)
  print("sum(wgt)="+sum(wgt))
The output looks like: 
Variable: wgt
Type: double
Total Size: 288 bytes
            36 values
Number of Dimensions: 1
Dimensions and sizes:   [lat | 36]
Coordinates:
            lat: [-87.5..87.5]
Number Of Attributes: 1
  long_name :   latitude weight

=======
         lat      wgt
(0)     -87.5   0.0038053
(1)     -82.5   0.0113869
(2)     -77.5   0.0188819
[snip]
(16)     -7.5   0.0864924
(17)     -2.5   0.0871557
(18)      2.5   0.0871557
(19)      7.5   0.0864924
[snip]
(33)     77.5   0.0188819
(34)     82.5   0.0113869
(35)     87.5   0.0038053
=======
(0)     sum(wgt)=2
Example 2

Consider a variable lat that spans 90S to 90N [5 deg spacing]. 

  wgt  = latRegWgt(lat, "float", 0)

  printVarSummary(wgt)
  print(lat+"    "+wgt)
  print("sum(wgt)="+sum(wgt))
The edited output looks like: 
Variable: wgt
Type: float
Number of Dimensions: 1
Dimensions and sizes:   [lat | 37]
Coordinates:
            lat: [-90.0..90.0]
Number Of Attributes: 1
  long_name :   latitude weight

=======
         lat      wgt
(0)     -90   0.000951778
(1)     -85   0.00760336
(2)     -80   0.0151489
[snip]
(16)    -10   0.0859134
(17)     -5   0.0869068
(18)      0   0.0872388
(19)      5   0.0869068
(20)     10   0.0859134
[snip]
(34)     80   0.0151489
(35)     85   0.00760336
(36)     90   0.000951778
=======
(0)     sum(wgt)=2