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DCL:MATH2:SHTLIB: Spherical Harmonic Functions: Explanation of Subroutines

4.3.5 SHTW2G

1.

Function

Performs the inverse Fourier transformation, which corresponds to the latter half of the spectral transformation.

2.

Definition

An inverse Fourier transformation:

is performed on wave data created by SHTS2W.

3.

Call

SHTW2G(MM,JM,IM,W,G,WORK)

4.

Explanation of Parameters

MM	(I)	Input parameter. The cut-off wavenumber (M).
JM	(I)	Input parameter. 1/2 of the NS partition number (J)
IM	(I)	Input parameter. 1/2 of the EW partition number (I)
W	(R)	Input parameter. Wave data. (For length and arrangement of array, see SHTS2W.)
G	(R)	Output parameter. Grid data.
		An array of length (2*IM+1)*(2*JM+1). (See Notes below for order of array.)
WORK	(R)	Working area initialized by SHTINT.

5.

Notes

(a)

When G(-IM:IM,-JM:JM) is declared in advance, G(&lambda_i、&phi_j) will be stored in G(I,J). (For definitions of &lambda_i、&phi_j , see "Summary.")

(b)

Specifying M1=0 and M2=MM is equivalent to calling SHTS2W.