corm1d(3F)

NAME
     SCORM1D, DCORM1D, CCORM1D, ZCORM1D - N 1D convolutions in the time
     domain.

FORTRAN SPECIFICATION
     subroutine SCORM1D( f, incf, ldf, ifx0, n_fx, ny,
                         g, incg,      igx0, n_gx,
                         h, inch, ldh, ihx0, n_hx )

     integer             incf, ldf, ifx0, n_fx, ny,
                         incg, igx0, n_gx,
                         inch, ldh, ihx0, n_hx

     real                f(ldf,ny), g(*), h(ldh,ny)


     subroutine DCORM1D( f, incf, ldf, ifx0, n_fx, ny,
                         g, incg,      igx0, n_gx,
                         h, inch, ldh, ihx0, n_hx )

     integer             incf, ldf, ifx0, n_fx, ny,
                         incg, igx0, n_gx,
                         inch, ldh, ihx0, n_hx

     double precision    f(ldf,ny), g(*), h(ldh,ny)


     subroutine CCORM1D( f, incf, ldf, ifx0, n_fx, ny,
                         g, incg,      igx0, n_gx,
                         h, inch, ldh, ihx0, n_hx )

     integer             incf, ldf, ifx0, n_fx, ny,
                         incg, igx0, n_gx,
                         inch, ldh, ihx0, n_hx

     complex             f(ldf,ny), g(*), h(ldh,ny)


     subroutine ZCORM1D( f, incf, ldf, ifx0, n_fx, ny,
                         g, incg,      igx0, n_gx,
                         h, inch, ldh, ihx0, n_hx )

     integer             incf, ldf, ifx0, n_fx, ny,
                         incg, igx0, n_gx,
                         inch, ldh, ihx0, n_hx

     double complex      f(ldf,ny), g(*), h(ldh,ny)

C SPECIFICATION
     #include <conv.h>

     void scorm1d( float *f, int incf, int lsf, int ifx0, int n_fx,
                   int n_seq,
                   float *g, int incg, int igx0, int n_gx,
                   float *h, int inch, int ldh, int ihx0, int n_hx )

     void dcorm1d( double *f, int incf, int ldf, int ifx0, int n_fx,
                   int n_seq,
                   double *g, int incg, int igx0, int n_gx,
                   double *h, int inch, int ldh, int ihx0, int n_hx )

     void ccorm1d( complex *f, int incf, int ldf, int ifx0, int n_fx,
                   int n_seq,
                   complex *g, int incg, int igx0, int n_gx,
                   complex *h, int inch, int ldh, int ihx0, int n_hx )

     void zcorm1d( zomplex *f, int incf, int ldf, int ifx0, int n_fx,
                   int n_seq,
                   zomplex *g, int incg, int igx0, int n_gx,
                   zomplex *h, int inch, int ldh, int ihx0, int n_hx )



DESCRIPTION
     SCORM1D, DCORM1D, CCORM1D and DCORM1D compute N 1D convolutions in the
     time domain :

                h(i,j) = Sum[ f(k,j) * g(i-k) ] with j=1,...,N

     _CORM1D can be used instead of _COR2D when the 2D filter can be
     decomposed into the convolution of two 1D filters.

     For example:
         ------------------   ------------------       ------------------
         | 0.25 -.50 0.25 |   | 0.   -.50 0.   |       | 0.   0.   0.   |
         | -.50 1.00 -.50 | = | 0.   1.00 0.   |  (*)  | -.50 1.00 -.50 |
         | 0.25 -.50 0.25 |   | 0.   -.50 0.   |       | 0.   0.   0.   |
         |________________|   |________________|       |________________|

     In these special cases, filtering an Image (NxN) by a Filter (MxM) can
     requires:
          only           2 * M * N * N  flop (using "dcorm1d" twice)
          as much as     M * M * N * N  flop (using "dcor2d")

USAGE:
     1. Suppose you want to:
            filter a 2D "image" f(0:449,0:699) along the first dimension ,
        by  a 1D filter g(-15:15),
            put the result in h(0:299,0:699),
        you can use:

           call dcorm1d(   f(0,0), 449-0+1, 1, 0, 449-0+1, 699+1,
                           g(-15), 1, -15, 15-(-15)+1,
          $                h(0, 0), 229-0+1, 0, 299-0+1 )

     2. Suppose you want to:
            filter a 2D "image" f(0:449,0:699) along the Second dimension ,
        by  the Fisrt line of g(0:149,-15:15),
            put the result in h(-25:449,0:699),
        you can use:

           call dcorm1d(   f(0, 0), 699-0+1, 1, 0, 449-0+1,
          $                g(0, -15), 1, 149-25+1, -15, 15,
          $                h(0, 0), 449-0+1, 1, 0, 449-0+1 )


PARAMETERS
     f       Vector containing the 2D sequence "f"

     incf    Increment between two successive values of "f"

     ldf     Increment between two successive 1D sequnce of "f"

     ifx0    Index of the first element of each 1D sequence of "f"

     n_fx    Number of elements of each sequence of "f"

     ny      Number of 1D sequences to filter


     g       Vector containing the 1D sequence "g"

     incg    Increment between two successive values of "g"

     igx0    Index of the first element of each 1D sequence of "g"

     n_gx    Number of elements of Each sequence of "g"


     h       Vector containing the 2D sequence "h"

     inch    Increment between two successive values of "h"

     ldh     Increment between two successive 1D sequnce of "h"
     ihx0    Index of the first element of each 1D sequence of "h"

     n_hx    Number of elements of Each sequence of "h"



IMPORTANT NOTE:
           The array pointers must all point to the first element of the
           array "(ifx0,ify0)", "(igx0,igy0)" and "(ihx0,ihy0)". If "f"
           for example is defined as
                dimension f(-25:45,10:21)
           Then "dcorm1d" must be called with the following parameters
                call dcorm1d( f(-25,10),(45-(-25)+1),-25,45,10,21 ... )


AUTHORS
          Jean-Pierre Panziera, 1/12/93.