gd_native_type(3)

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 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 native 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, otherwise: GD_FLOAT64;

MULTIPLY or DIVIDE Entry:
    if either input field is complex valued: GD_COMPLEX128, otherwise: 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 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 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_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_BAD_SCALAR
    A non-literal scalar used in the definition of the field or one of its inputs was not found, or was not a CONST or CARRAY field.

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 dependency in field specification in the dirfile.

The dirfile error may be retrieved by calling gd_error(3). A descriptive error string for the last error encountered can be obtained from a call to gd_error_string(3).

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