ms_genfactmult.3

C编写的格式转换程序

.TH MS_GENFACTMULT 3 2004/11/22 "Libmseed API"
.SH DESCRIPTION
Generate SEED sample rate factor and multiplier

.SH SYNOPSIS
.nf
.B #include <libmseed.h>

.BI "int  \fBms_genfactmult\fP ( double " samprate ", int16_t *" factor ",
.BI "                      int16_t *" multiplier " );"

.BI "int  \fBms_ratapprox\fP ( double " real ", int *" num ", int *" den ",
.BI "                    int " maxval ", double " precision " );"
.fi

.SH DESCRIPTION
\fBms_genfactmult\fP generates an appropriate SEED sample rate
\fIfactor\fP and \fImultiplier\fP pair from a double precision sample
rate (\fIsamprate\fP).  The factor and multiplier are cast as int16_t
because that is the integer size needed for the fixed section of the
SEED data header.

If the input sample rate is already integer (within 0.000001) it will
be placed into the factor and the multiplier will be set to 1.

An error will be produced if the sample rate is very high (> 32727) or
negative.

\fBms_ratapprox\fP finds an approximate rational number for a real
through continued fraction expansion.  Given a double precision
\fIreal\fP the routine tries to find a rational in numerator
(\fInum\fP) and denominator (\fIden\fP) form whose absolute values are
not larger than \fImaxval\fP while trying to reach a specified
\fIprecision\fP.

.SH RETURN VALUES
\fBms_genfactmult\fP returns 0 on success and -1 on error.

\fBms_ratapprox\fP returns the number of iterations performed.

.SH AUTHOR
.nf
Chad Trabant
IRIS Data Management Center
.fi