dirfile_alter_const (3) - Linux Manuals

The dirfile_alter_clincom() and dirfile_alter_cpolynom() functions are identical to dirfile_alter_lincom() and dirfile_alter_polynom(), except they take complex scalar parameters, instead of purely real values. This only matters for the input of new parameters; if the scalar parameters are not changed (by passing NULL instead of a list of scalars), the functions can be used interchangeably, regardless of whether the altered field has complex scalar parameters or not.

If the corresponding parameters are to be changed, the dirfile_alter_lincom() and dirfile_alter_clincom() functions take pointers to three arrays of length n_fields containing the input field names (in_fields), the gain factors (m or cm), and the offset terms (b or cb). Similarly, dirfile_alter_polynom() and dirfile_alter_cpolynom() take an array of length poly_ord + 1 containing the polynomial co-efficients (a or ca).

Some field parameters have special values which indicate no change should be made to the parameter. Specifically, if any of the string parameters or m,~b, or a (cm,~cb, or ca) are NULL, the old values will be retained. Similarly, if spf, n_fields, or numbits is zero, or if bitnum is -1, or if data_type, or const_type are equal to GD_NULL, these parameters will not be modified.

All field parameters introduced with this interface must contain numerical parameters. Field parameters which are CONST cannot be introduced with these functions. To do that, use dirfile_alter_entry(3), dirfile_alter_spec(3) or dirfile_malter_spec(3), as appropriate.

If rename_table is non-zero, the look-up table referenced by the LINTERP field will be renamed to the path given by table. If recode is non-zero, the binary file associated with the RAW field will be re-encoded to reflect the new field parameters.

See NOTES below for information on using dirfile_alter_clincom() and dirfile_alter_cpolynom() in the C89 GetData API.

RETURN VALUE

The gd_bit_t type is a signed 16-bit integer type. The gd_shift_t type is a signed 64-bit integer type. The gd_spf_t type is an unsigned 16-bit integer type.

GD_E_ACCMODE

The specified dirfile was opened read-only.

GD_E_ALLOC

The library was unable to allocate memory.

GD_E_BAD_CODE

The field specified by field_code was not found.

GD_E_BAD_DIRFILE

The supplied dirfile was invalid.

GD_E_BAD_ENTRY

One or more of the field parameters specified was invalid.

GD_E_BAD_FIELD_TYPE

The field specified by field_code was of the wrong type for the function called.

GD_E_BAD_TYPE

The data_type or const_type argument was invalid.

GD_E_PROTECTED

The metadata of the fragment was protected from change. Or, a request to translate the binary file associated with a RAW field was attempted, but the data of the fragment was protected.

GD_E_RAW_IO

An I/O error occurred while translating the binary file associated with a modified RAW field, or an I/O error occurred while attempting to rename a LINTERP table file.

GD_E_UNKNOWN_ENCODING

The encoding scheme of the specified format file fragment is not known to the library. As a result, the library was unable to translate the binary file be associated with a modified RAW field.

GD_E_UNSUPPORTED

The encoding scheme of the specified format file fragment does not support translating the empty binary file associated with a modified RAW field. The dirfile error may be retrieved by calling get_error(3). A descriptive error string for the last error encountered can be obtained from a call to get_error_string(3).

NOTES

#define GETDATA_C89_API
#include <getdata.h>

int dirfile_alter_clincom(DIRFILE *dirfile, const char *field_code,
int n_fields, const char **in_fields, const double *cm,
const double *cb);
int dirfile_alter_cpolynom(DIRFILE *dirfile, const char *field_code,
int poly_ord, const char *in_fields, const double *ca);