gd_native_type(3) GETDATA gd_native_type(3)NAMEgd_native_type — returns the native data type of a field in a dirfile
SYNOPSIS
#include <getdata.h>
gd_type_t gd_native_type(DIRFILE *dirfile, const char *field_code);
DESCRIPTION
The gd_native_type() function queries a dirfile(5) database specified
by dirfile and returns the native data type of the field field_code,
which may contain a representation suffix.
The dirfile argument must point to a valid DIRFILE object previously
created by a call to gd_open(3).
The native data type of a field of a given entry type is calculated as:
BIT or INDEX Entry:
GD_UINT64;
CONST or CARRAY Entry:
the data type of the field;
LINCOM or POLYNOM Entry:
if any of the scalar parameters is complex valued, or if the na‐
tive data type of any of the input fields is complex valued:
GD_COMPLEX128, otherwise: GD_FLOAT64;
LINTERP Entry:
if the look-up table is complex valued: GD_COMPLEX128, other‐
wise: GD_FLOAT64;
MPLEX or WINDOW Entry:
the native data type of the data field;
MULTIPLY or DIVIDE Entry:
if either input field is complex valued: GD_COMPLEX128, other‐
wise: GD_FLOAT64;
PHASE Entry:
the native data type of the input field;
RAW Entry:
the data type of the raw data on disk;
RECIP Entry:
if the dividend or the native data type of the input field is
complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;
SBIT Entry:
GD_INT64;
STRING Entry:
GD_NULL.
Furthermore, if the supplied field_code contains a representation suf‐
fix, and the native data type of the field is complex valued, the na‐
tive type returned will be the corresponding real valued type.
RETURN VALUE
Upon successful completion, gd_native_type() returns the native data
type of the field code specified. This will be one of the symbols:
GD_NULL, GD_UINT8, GD_INT8, GD_UINT16, GD_INT16, GD_UINT32,
GD_INT32, GD_FLOAT32, GD_FLOAT64, GD_COMPLEX64, GD_COMPLEX128.
The meanings of these symbols are explained in the gd_getdata(3) manual
page. On error, it returns GD_UNKNOWN and sets the dirfile error to a
non-zero error value. Possible error values are:
GD_E_ALLOC
The library was unable to allocate memory.
GD_E_BAD_CODE
The field specified by field_code or one of the fields it uses
as input was not found in the database.
GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
GD_E_BAD_REPR
The representation suffix specified in field_code, or in one of
its input fields, was not recognised.
GD_E_DIMENSION
A scalar field was found where a vector field was expected.
GD_E_OPEN_LINFILE
An error occurred while trying to read a LINTERP table from
disk.
GD_E_RECURSE_LEVEL
Too many levels of recursion were encountered while trying to
resolve field_code. This usually indicates a circular depen‐
dency in field specification in the dirfile.
The dirfile error may be retrieved by calling gd_error(3). A descrip‐
tive error string for the last error encountered can be obtained from a
call to gd_error_string(3).
SEE ALSOdirfile(5), gd_open(3), gd_getdata(3), gd_error(3), gd_error_string(3)Version 0.8.0 17 August 2012 gd_native_type(3)
