User`s guide

SdfVectHdr
Syntax int SdfVectHdr (short fn, short dataNo, short rowNo,
short colNo, struct SDF_VECTOR_HDR far *vectHdr);
Returns an integer(short) of zero or minus one. A return of 0 indicates no error; a return of
-1 indicates an error.
This function reads the vector-header information from an open SDF file, where fn is the number of the
open SDF file (for details, see SdfOpen). The information is put in the SDF_VECTOR_HDR structure,
where vectHdr is the pointer to the structure.
Note See SdfYdata for a description of the parameters used with this function.
Two fields in the vector header record, the_CHANNEL_record[0] and the_CHANNEL_record[1],
contain indexes to channel header records containing the channel numbers associated with that vector.
Although the the_CHANNEL_record[0] and the_CHANNEL_record[1] fields do not refer to actual
channel numbers themselves, in the HP 3566A/3567A the channel number is always 1 plus the value in
these fields, since channel header records are a contiguous block starting from channel 1 and the indexes
to the channel header records start at 0. For single channel measurements, the_CHANNEL_record[1]
will always be –1.
The vector header record is mainly used to store the indexes of associated channel header records and the
exponents (power) applied to the corresponding trace data.
Using SDF Data with C Programs
SdfVectHdr
6-8