SYNOPSIS

#include <getdata.h> int gd_madd_bit(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field, gd_bit_t bitnum, gd_bit_t numbits); int gd_madd_carray(DIRFILE *dirfile, const char *parent, const char *field_name, gd_type_t const_type, size_t array_len, gd_type_t data_type, void *value); int gd_madd_clincom(DIRFILE *dirfile, const char *parent, const char *field_name, int n_fields, const char **in_fields, const double complex *cm, const double complex *cb); int gd_madd_const(DIRFILE *dirfile, const char *parent, const char *field_name, gd_type_t const_type, gd_type_t data_type, void *value); int gd_madd_cpolynom(DIRFILE *dirfile, const char *parent, const char *field_name, int poly_ord, const char *in_field, const double complex *ca); int gd_madd_crecip(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field, double complex cdividend, int fragment_index); int gd_madd_divide(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field1, const char *in_field2); int gd_madd_lincom(DIRFILE *dirfile, const char *parent, const char *field_name, int n_fields, const char **in_fields, const double *m, const double *b); int gd_madd_linterp(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field, const char *table); int gd_madd_multiply(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field1, const char *in_field2); int gd_madd_polynom(DIRFILE *dirfile, const char *parent, const char *field_name, int poly_ord, const char *in_field, const double *a); int gd_madd_phase(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field, gd_shift_t shift); int gd_madd_recip(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field, double dividend, int fragment_index); int gd_madd_sbit(DIRFILE *dirfile, const char *parent, const char *field_name, const char *in_field, gd_bit_t bitnum, gd_bit_t numbits); int gd_madd_string(DIRFILE *dirfile, const char *parent, const char *field_name, const char *value);

DESCRIPTION

These functions provide alternatives to using the gd_madd() function to add a new metafield of the indicated type under the parent field given by parent in the dirfile specified by dirfile.

In all of these calls, field_name indicates the name of the field to be added. It should not be the full <parent-field>/<meta-field> field code. The meaning and valid types of other arguments may be obtained from the gd_entry(3) and dirfile-format(5) manual pages.

The gd_madd_clincom() and gd_madd_cpolynom() functions are identical to gd_madd_lincom() and gd_madd_polynom(), except they take complex scalar parameters, instead of purely real values.

The gd_madd_lincom() and gd_madd_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, gd_madd_polynom() and gd_madd_cpolynom() take an array of length poly_ord + 1 containing the polynomial co-efficients (a or ca).

The gd_madd_string(),\~gd_madd_carray, and gd_madd_const() functions both add the field and set the value of the field to value. For gd_madd_const() and gd_madd_carray(), the const_type argument specifies the storage type for the const, while data_type specifies the data type of the value pointed to by 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.

All fields added with this interface must contain numerical parameters. Fields with scalar fields as parameters cannot be added with these functions. Those fields must be added with gd_madd(3) or gd_madd_spec(3).

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

RETURN VALUE

On success, any of these functions returns zero. On error, -1 is returned and the dirfile error is set to a non-zero error value. Possible error values are:

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_name argument contained invalid characters. Alternately, the parent field code was not found, or was already a metafield.

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_TYPE

The data_type or const_type argument provided to gd_madd_const() or gd_madd_carray() was invalid.

GD_E_DUPLICATE

The field_name provided duplicated that of an already existing field.

GD_E_PROTECTED

The metadata of the fragment was protected from change.

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).

NOTES

The C89 GetData API provides different prototypes for gd_madd_clincom(),\~gd_madd_cpolynom(), and gd_madd_crecip():

#define GD_C89_API
#include <getdata.h>
int gd_madd_clincom(DIRFILE *dirfile, const char *parent,
const char *field_name, int n_fields, const char **in_fields,
const double *cm, const double *cb);
int gd_madd_cpolynom(DIRFILE *dirfile, const char *parent,
const char *field_name, int poly_ord, const char *in_field,
const double *ca);
int gd_madd_crecip(DIRFILE *dirfile, const char *parent,
const char *field_name, const char *in_field,
double cdividend[2], int fragment_index);

In this case, the array pointers passed as cm, cb or ca should have twice as many (purely real) elements, consisting of alternating real and imaginary parts for the complex data. For example, ca[0] should be the real part of the first co-efficient, ca[1] the imaginary part of the first co-efficient, ca[2] the real part of the second co-efficient, ca[3] the imaginary part of the second co-efficient, and so on. Similarly, the cdividend parameter becomes a double precision array of length two.

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