table of contents
gd_native_type — returns the native data type of a field in a Dirfile
gd_type_t gd_native_type(DIRFILE *dirfile, const char *field_code);
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:
- the data type of the field;
- if either input field is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;
- the data type of the input CARRAY;
- 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;
- if the look-up table is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;
- the native data type of the data field;
- the native data type of the input field;
- the data type of the raw data on disk;
- if the dividend or the native data type of the input field is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;
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.
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:
- The library was unable to allocate memory.
- The field specified by field_code or one of the fields it uses as input was not found in the database.
- The supplied dirfile was invalid.
- A scalar field was found where a vector field was expected.
- An error occurred while trying to read a LINTERP table from disk.
- A LINTERP table was malformed.
- 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).
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.
gd_error(3), gd_error_string(3) gd_getdata(3), gd_open(3), dirfile(5)
|25 January 2017||Version 0.10.0|