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diff --git a/noao/digiphot/ptools/doc/pcalc.hlp b/noao/digiphot/ptools/doc/pcalc.hlp new file mode 100644 index 00000000..36d06229 --- /dev/null +++ b/noao/digiphot/ptools/doc/pcalc.hlp @@ -0,0 +1,86 @@ +.help pcalc May93 noao.digiphot.ptools +.ih +NAME +pcalc - perform an arithmetic operation on a field in a list of apphot/daophot +databases +.ih +USAGE +pcalc infiles field value +.ih +PARAMETERS +.ls infiles +The APPHOT/DAOPHOT database(s) containing the field to be recomputed. +.le +.ls field +The field to be recomputed. Field must be an integer or real field +in the input file(s). +.le +.ls value +The arithmetic expression used to recompute the specified field. +Value may be an integer or real expression but must match the data +type of field. The functions real and int may be used to do type +conversions. +.le + +.ih +DESCRIPTION + +PCALC reads in the values of the \fIfield\fR keyword +from a set of APPHOT/DAOPHOT databases, replaces the old values +with new values equal to the value of the arithmetic expression \fIvalue\fR, +and updates the databases(s). + +PCALC is script task which calls TXCALC is the input file is an +APPHOT/DAOPHOT text database or TBCLAC if APPHOT/DAOPHOT is a tables +database. +If the input file is a text database, the expression \fIvalue\fR consists +of variables which are the field names +specified by the #N keywords or the parameters specified by the +#K keywords in the APPHOT/DAOPHOT text databases. +Only keywords beginning with #N can actually be replaced. +If the input file is an ST tables database, the expression \fIvalue\fR +consists of the table column names. + +The supported +arithmetic operators and functions are briefly described below. + +.nf +addition + subtraction - +multiplication * division / +negation - exponentiation ** +absolute value abs(x) cosine cos(x) +sine sin(x) tangent tan(x) +arc cosine acos(x) arc sine asin(x) +arc tangent atan(x) arc tangent atan2(x,y) +exponential exp(x) square root sqrt(x) +natural log log(x) common log log10(x) +minimum min(x,y) maximum max(x,y) +convert to integer int(x) convert to real real(x) +nearest integer nint(x) modulo mod(x) +.fi + +.ih +EXAMPLES + +1. Change the XCENTER and YCENTER fields to XCENTER + 5.4 and YCENTER + 10.3 +respectively in a file produced by the apphot package center task. + +.nf + pt> pcalc m92.ctr.1 xcenter "xcenter+5.4" + pt> pcalc m92.ctr.1 ycenter "ycenter+10.3" +.fi + +2. Add a constant to the computed magnitudes produced by nstar. + +.nf + pt> pcalc n4147.nst.2 mag "mag+3.457" +.fi + +.ih +BUGS +TXCALC does not allow arrays in the expression field. + +.ih +SEE ALSO +ptools.tbcalc,tables.tcalc,ptools.pcalc +.endhelp |