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gaus_lobat

Computes gaussian latitudes and weights using Gauss-Lobatto quadrature.

Prototype

	function gaus_lobat (
		nlat [1] : integer   
	)

	return_val [nlat,2] :  double

Arguments

nlat

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

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
Example 2

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