NAME

gd_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 determines the native type of data specified by 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

INDEX

GD_UINT64;

CONST

CARRAY

the data type of the field;

DIVIDE

MULTIPLY

if either input field is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;

INDIR

the data type of the input CARRAY;

LINCOM

POLYNOM

if any of the scalar parameters is complex valued, or if the native data type of any of the input fields is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;

LINTERP

if the look-up table is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;

MPLEX

WINDOW

the native data type of the data field;

PHASE

the native data type of the input field;

RAW

the data type of the raw data on disk;

RECIP

if the dividend or the native data type of the input field is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;

SARRAY

SINDIR

STRING

GD_STRING;

SBIT

GD_INT64.

Furthermore, if the supplied field_code contains a representation suffix, and the native data type of the field is complex valued, the native 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 equal one of the symbols:

GD_UINT8, GD_INT8, GD_UINT16, GD_INT16, GD_UINT32, GD_INT32, GD_FLOAT32, GD_FLOAT64, GD_COMPLEX64, GD_COMPLEX128, GD_STRING.

The meanings of these symbols are explained in the gd_getdata(3) manual page.

On error, this function returns GD_UNKNOWN and stores a negative-valued error code in the DIRFILE object which may be retrieved by a subsequent call to gd_error(3). Possible error codes 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_DIMENSION

A scalar field was found where a vector field was expected.

GD_E_IO

An error occurred while trying to read a LINTERP table from disk.

GD_E_LUT

A LINTERP table was malformed.

GD_E_RECURSE_LEVEL

Too many levels of recursion were encountered while trying to resolve field_code. This usually indicates a circular dependency in field specification in the dirfile.

A descriptive error string for the error may be obtained by calling gd_error_string(3).

HISTORY

The get_native_type() function appeared in GetData-0.6.0. The return type for STRING fields was GD_NULL.

In GetData-0.7.0, this function was renamed to gd_native_type().

Before GetData-0.10.0, the return type for STRING fields was GD_NULL.

SEE ALSO

gd_error(3), gd_error_string(3) gd_getdata(3), gd_open(3), dirfile(5)