Program:      RESTORE

Purpose:      This program restores the residuals created by CLEAN.

Category:     CLEAN, RADIO, TABLES

File:         restore.c

Author:       K. Begeman

Description:  The restoration is done with a truncated gaussian beam
              {maximum 129*129 grid units}.  It uses existing components
              found by CLEAN.  The residual is overwritten by the
              restored image.

Keywords:

   INSET=     Set and subset(s) of residual(s).
              Usually the set is the same as the output set created by
              CLEAN. Maximum number of subsets is 2048. The subset
              dimension may be one or two.

   BEAM=      Half power beam width of clean beam in arcsecs.
              For a one-dimensional subset, enter the HPBW in arcsec.
              For a two-dimensional subset, first give HPBW along
              majo axis, then HPBW along minor axis. If the header
              items BMMIN and BMMAJ are present, their value will be
              the default.

   BEAMPA=    Position angle of major axis of clean beam in degrees.
              Only asked when subsets are two-dimensional.
              In general only needed for VLA maps. If the header item
              BMPA is present, its value will be the default.

** CLEANBOX=  The size of cleaned area in the residual map(s) [whole subset].
              The restoration takes place in this area.

** FACTOR=    Beam Multiplication Factor [1.0].
              With FACTOR=-1.0 you can undo a previous restoration.

Notes:        1. When you want to save the residual map, use COPY.
              2. There is no limit on the number of components in a file,
                 except the available memory in the machine.
              3. When you enter a zero for the half power beamwidth, the
                 gaussian  beam will be changed into a delta function
                 along that axis. This is used for creating component
                 maps from component tables.

Updates:      Jan 23, 1982: KGB Original program created.
              Mar 24, 1982: KGB Original document created.
              Dec 02, 1982: KGB Larger read buffer.
              Sep 12, 1983: KGB Allowed for zero beam size.
              Aug 22, 1986: KGB Larger buffer for clean bean.
              Mar 24, 1988: AXL Document standardized.
              May 13, 1989: KGB Allow negative grid separations.
              Sep  7, 1991: KGB Migrated to UNIX GIPSY.
              Dec 11, 1991: KGB Cancel replaced by reject.
              Apr  8, 1992: KGB One-dimensional restore implemented.
              Feb  1, 2000: JPT Increased number of subsets.