2 ***********************************************************
3 $SNARK_Header: S N A R K 1 4 - A PICTURE RECONSTRUCTION PROGRAM $
4 $HeadURL: svn://dig.cs.gc.cuny.edu/snark/trunk/src/snark/foru_ftmap.cpp $
5 $LastChangedRevision: 85 $
6 $Date: 2014-07-02 16:07:08 -0400 (Wed, 02 Jul 2014) $
8 ***********************************************************
10 PURPOSE: REARRANGE THE PROJECTION DATA (IN VFROM) IN A FORM
11 SUITABLE FOR FAST FOURIER ROUTINES (I.E. CHANGE THE
12 PHASE SO THAT THE ORIGIN IS THE 1ST ELEMENT IN ARRAY )
13 AND PUT INTO THE ARRAY VTO
15 // bug79 - problem with fourier algorithm
23 void foru_class::ftmap(REAL* vfrom, REAL* vto, BOOLEAN revers)
29 Fourie.midr = Fourie.nsize1 / 2 - 1;
31 // IF REVERS IS TRUE ,REVERSE THE PROJECTION DATA (SEE ALSO PRJTRN)
38 for (i = 0; i <= kh; i++)
39 { // bug79 - swr 2/11/05
40 vto[i] = vfrom[Fourie.midr + i];
45 for (i = kl; i < Fourie.nsize1; i++)
47 vto[i] = vfrom[i - Fourie.midr - 2]; // bug79 - swr 2/11/05
52 for (i = 0; i <= Fourie.midr; i++)
54 vto[i] = vfrom[Fourie.midr - i];
59 for (i = kl; i < Fourie.nsize1; i++)
61 vto[i] = vfrom[Fourie.nsize1 + Fourie.midr - i];