gd_add_linterp (3)

#include <getdata.h> int gd_add_bit(DIRFILE *dirfile, const char *field_name, const char *in_field, gd_bit_t bitnum, gd_bit_t numbits, int fragment_index); int gd_add_carray(DIRFILE *dirfile, const char *field_name, gd_type_t const_type, size_t array_len, gd_type_t data_type, void *value, int fragment_index); int gd_add_clincom(DIRFILE *dirfile, const char *field_name, int n_fields, const char **in_fields, const double complex *cm, const double complex *cb, int fragment_index); int gd_add_const(DIRFILE *dirfile, const char *field_name, gd_type_t const_type, gd_type_t data_type, void *value, int fragment_index); int gd_add_cpolynom(DIRFILE *dirfile, const char *field_name, int poly_ord, const char *in_fields, const double complex *ca, int fragment_index ); int gd_add_crecip(DIRFILE *dirfile, const char *field_name, const char *in_field, double complex cdividend, int fragment_index); int gd_add_divide(DIRFILE *dirfile, const char *field_name, const char *in_field1, const char *in_field2, int fragment_index); int gd_add_lincom(DIRFILE *dirfile, const char *field_name, int n_fields, const char **in_fields, const double *m, const double *b, int fragment_index); int gd_add_linterp(DIRFILE *dirfile, const char *field_name, const char *in_field, const char *table, int fragment_index); int gd_add_multiply(DIRFILE *dirfile, const char *field_name, const char *in_field1, const char *in_field2, int fragment_index); int gd_add_phase(DIRFILE *dirfile, const char *field_name, const char *in_field, gd_shift_t shift, int fragment_index); int gd_add_polynom(DIRFILE *dirfile, const char *field_name, int poly_ord, const char *in_fields, const double *a, int fragment_index ); int gd_add_raw(DIRFILE *dirfile, const char *field_name, gd_type_t data_type, gd_spf_t spf, int fragment_index); int gd_add_recip(DIRFILE *dirfile, const char *field_name, const char *in_field, double dividend, int fragment_index); int gd_add_sbit(DIRFILE *dirfile, const char *field_name, const char *in_field, gd_bit_t bitnum, gd_bit_t numbits, int fragment_index); int gd_add_string(DIRFILE *dirfile, const char *field_name, const char *value, int fragment_index);

These functions provide alternatives to using the gd_add(3) or gd_add_spec(3) functions to add a new field of the indicated type to the dirfile specified by dirfile.

In all of these calls, field_name indicates the name of the field to be added. Further, fragment_index is the index of the format specification fragment into which the field should be added. (To convert a fragment index to its file name, see gd_fragmentname(3).) The meaning and valid types of other arguments may be obtained from the gd_entry(3) and dirfile-format(5) manual pages.

The gd_add_clincom() and gd_add_cpolynom() functions are identical to gd_add_lincom() and gd_add_polynom(), except they take complex scalar parameters, instead of purely real values.

The gd_add_lincom() and gd_add_clincom() functions takes 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_add_polynom() and gd_add_cpolynom() take an array of length poly_ord + 1 containing the polynomial co-efficients (a or ca).

The gd_add_string(),\~gd_add_carry(), and gd_add_const() functions add the field and set the value of the field to value. For gd_add_const() and gd_add_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. The gd_spf_t type is an unsigned 16-bit integer type.

All fields added with this interface must contain literal parameters. Fields with scalar fields as parameters cannot be added with these functions. Those fields must be added with gd_add(3) or gd_add_spec(3).

See NOTES below for information on using gd_add_clincom(),\~gd_add_carray(), and gd_add_cpolynom() in the C89 GetData API.

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.

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_INDEX

The fragment_index argument was out of range.

GD_E_BAD_TYPE

The data_type or const_type argument provided to gd_add_raw() or gd_add_const(), was invalid.

GD_E_BOUNDS

The array_len parameter provided to gd_add_carray() was greater than GD_MAX_CARRAY_LENGTH.

GD_E_DUPLICATE

The field_name provided duplicated that of an already existing field.

GD_E_INTERNAL_ERROR

An internal error occurred in the library while trying to perform the task. This indicates a bug in the library. Please report the incident to the GetData developers.

GD_E_PROTECTED

The metadata of the fragment was protected from change. Or, the creation of a RAW field was attempted and the data of the fragment was protected.

GD_E_RAW_IO

An I/O error occurred while creating an empty binary file to be associated with a newly added RAW field.

GD_E_UNKNOWN_ENCODING

The encoding scheme of the indicated format specification fragment is not known to the library. As a result, the library was unable to create an empty binary file to be associated with a newly added RAW field.

GD_E_UNSUPPORTED

The encoding scheme of the indicated format specification fragment does not support creating an empty binary file to be associated with a newly added RAW field.

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).

GetData artifically limits the number of elements in a CARRAY to the value of the symbol GD_MAX_CARRAY_LENGTH defined in getdata.h. This is done to be certain that the CARRAY won't overrun the line when flushed to disk. On a 32-bit system, this number is 2**24. It is larger on a 64-bit system.

The C89 GetData API provides different prototypes for gd_add_clincom(),\~gd_add_cpolynom(), and gd_add_crecip():

#define GD_C89_API
#include <getdata.h>
int gd_add_clincom(DIRFILE *dirfile, const char *field_name,
int n_fields, const char **in_fields, const double *cm,
const double *cb, int fragment_index);
int gd_add_cpolynom(DIRFILE *dirfile, const char *field_name,
int poly_ord, const char *in_fields, const double *ca,
int fragment_index );
int gd_add_crecip(DIRFILE *dirfile, 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.

gd_add(3), gd_add_spec(3), gd_error(3), gd_error_string(3), gd_madd_bit(3), gd_madd_carray(3), gd_madd_const(3), gd_madd_divide(3), gd_madd_lincom(3), gd_madd_linterp(3), gd_madd_multiply(3), gd_madd_phase(3), gd_madd_polynom(3), gd_madd_recip(3), gd_madd_sbit(3), gd_madd_string(3), gd_metaflush(3), gd_open(3), dirfile-format(5)