gaus_lobat

Computes Gaussian latitudes and weights using Gauss-Lobatto quadrature.

Prototype

	function gaus_lobat (
		nlat [1] : byte, short, integer or long   
	)

	return_val [nlat,2] :  double

Arguments

A scalar integer equal to the total number of latitude points. This may be odd or even.

As of version 6.0.0, this can be of type byte, short, integer or long.

Return value

A two dimensional array containing both the Gauss-Lobatto latitudes (first dimension) and the Gauss-Lobatto weights (second dimension). By default the returned values are of type double.

Description

Computes Gaussian latitudes and weights using Gauss-Lobatto quadrature. The max and min Gaussian latitudes will include the poles. The weights will sum to 2.0.

See Also

There are numerous other latitude/longitude functions.

Examples

Example 1

Generates Gauss-Lobatto latitudes and weights (type double) for a specified number of latitudes:

  nlat = 8  

  gau_info = gaus_lobat(nlat)   
  glat     = gau_info(:,0)  ; Gauss-Lobatto latitudes [ascending order] 
  gwgt     = gau_info(:,1)  ; Gauss-Lobatto weights  

Output:

          glat        gwgt      sum[gwgt]
         -------      ------     -------
    0  -90.00000     0.03571     0.03571
    1  -78.45661     0.21070     0.24642
    2  -53.25302     0.34112     0.58754
    3  -18.83693     0.41246     1.00000
    4   18.83693     0.41246     1.41246
    5   53.25302     0.34112     1.75358
    6   78.45661     0.21070     1.96429
    7   90.00000     0.03571     2.00000

Use doubletofloat to generate Gauss-Lobatto latitudes and weights (type float) for a specified number of latitudes:

  nlat     = 24     ; for globe
; conversion is embedded
  gau_info = doubletofloat(gaus_lobat(nlat)) 
  glat     = gau_info(:,0)                ; glat ==> float
  gwgt     = gau_info(:,1)                ; gwgt ==> float