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include <tbset.h>
include "tbtables.h"
# This routine copies the tscal & tzero values to COL_TSCAL & COL_TZERO.
#
# This routine will return without doing anything if:
# the table type isn't FITS
# the "true" data type is a floating type, or boolean, or text
# the input tscal & tzero are 1 & 0 respectively or are INDEFD.
#
# Unless the data type already is a floating type, it will be changed to
# real or double. If the actual data type in the table file is int, the
# apparent data type will be set to double; otherwise (i.e. short or byte),
# the apparent data type will be set to real.
#
# If the table is open, the TSCALi and TZEROi keywords will be added to
# the header (or updated, if they're already present).
#
# This is the interface routine; tbfscal is lower level.
#
# Phil Hodge, 23-Jun-2000 Subroutine created.
procedure tbcscal (tp, cp, tscal, tzero)
pointer tp # i: pointer to table struct
pointer cp # i: pointer to column struct
double tscal # i: scale factor for column
double tzero # i: zero offset for column
#--
int tdtype # "true" data type (we expect short or int)
int dtype # "apparent" data type
bool modify # true if either tscal or tzero differs from default
errchk tbfscal
begin
if (TB_TYPE(tp) != TBL_TYPE_FITS)
return # scaling parameters can't be used
dtype = COL_DTYPE(cp)
tdtype = COL_TDTYPE(cp)
# Scaling is only appropriate if the true data type in the table
# file is an integer type.
if (tdtype == TBL_TY_REAL || tdtype == TBL_TY_DOUBLE ||
tdtype == TBL_TY_BOOL || tdtype < 0) {
return
}
modify = false # initial value
if (tscal != 1.d0 && !IS_INDEFD(tscal)) {
COL_TSCAL(cp) = tscal
modify = true
}
if (tzero != 1.d0 && !IS_INDEFD(tzero)) {
COL_TZERO(cp) = tzero
modify = true
}
if (!modify)
return # nothing to do
# Change the data type to a floating type, if it isn't already.
if (dtype != TBL_TY_REAL && dtype != TBL_TY_DOUBLE) {
if (tdtype == TBL_TY_INT)
COL_DTYPE(cp) = TBL_TY_DOUBLE
else
COL_DTYPE(cp) = TBL_TY_REAL
}
# Write these values to keywords TSCALi and TZEROi.
if (TB_IS_OPEN(tp))
call tbfscal (tp, cp)
end
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