6.4.2 Read or Write Standard Header Routines
These subroutines provide a simple method of reading or writing most of
the keyword values that are normally required in a FITS files. These
subroutines are provided for convenience only and are not required to
be used. If preferred, users may call the lower-level subroutines
described in the previous section to individually read or write the
required keywords. Note that in most cases, the required keywords such
as NAXIS, TFIELD, TTYPEn, etc, which define the structure of the HDU
must be written to the header before any data can be written to the
image or table.
- 1
- Put the primary header or IMAGE extension keywords into the CHU.
There are 2 available routines: The simpler FTPHPS routine is
equivalent to calling ftphpr with the default values of SIMPLE = true,
pcount = 0, gcount = 1, and EXTEND = true. PCOUNT, GCOUNT and EXTEND
keywords are not required in the primary header and are only written if
pcount is not equal to zero, gcount is not equal to zero or one, and if
extend is TRUE, respectively. When writing to an IMAGE extension, the
SIMPLE and EXTEND parameters are ignored.
FTPHPS(unit,bitpix,naxis,naxes, > status)
FTPHPR(unit,simple,bitpix,naxis,naxes,pcount,gcount,extend, > status)
- 2
- Get primary header or IMAGE extension keywords from the CHU. When
reading from an IMAGE extension the SIMPLE and EXTEND parameters are
ignored.
FTGHPR(unit,maxdim, > simple,bitpix,naxis,naxes,pcount,gcount,extend,
status)
- 3
- Put the ASCII table header keywords into the CHU. The optional
TUNITn and EXTNAME keywords are written only if the input string
values are not blank.
FTPHTB(unit,rowlen,nrows,tfields,ttype,tbcol,tform,tunit,extname, >
status)
- 4
- Get the ASCII table header keywords from the CHU
FTGHTB(unit,maxdim, > rowlen,nrows,tfields,ttype,tbcol,tform,tunit,
extname,status)
- 5
- Put the binary table header keywords into the CHU. The optional
TUNITn and EXTNAME keywords are written only if the input string
values are not blank. The pcount parameter, which specifies the
size of the variable length array heap, should initially = 0;
FITSIO will automatically update the PCOUNT keyword value if any
variable length array data is written to the heap. The TFORM keyword
value for variable length vector columns should have the form 'Pt(len)'
or '1Pt(len)' where `t' is the data type code letter (A,I,J,E,D, etc.)
and `len' is an integer specifying the maximum length of the vectors
in that column (len must be greater than or equal to the longest
vector in the column). If `len' is not specified when the table is
created (e.g., the input TFORMn value is just '1Pt') then FITSIO will
scan the column when the table is first closed and will append the
maximum length to the TFORM keyword value. Note that if the table
is subsequently modified to increase the maximum length of the vectors
then the modifying program is responsible for also updating the TFORM
keyword value.
FTPHBN(unit,nrows,tfields,ttype,tform,tunit,extname,varidat, > status)
- 6
- Get the binary table header keywords from the CHU
FTGHBN(unit,maxdim, > nrows,tfields,ttype,tform,tunit,extname,varidat,
status)