Provided by: libgetdata-dev_0.7.3-6_amd64 bug

NAME

       gd_alter_bit,   gd_alter_carray,   gd_alter_clincom,   gd_alter_const,  gd_alter_cpolynom,
       gd_alter_crecip, gd_alter_divide,  gd_alter_lincom,  gd_alter_linterp,  gd_alter_multiply,
       gd_alter_phase,  gd_alter_polynom,  gd_alter_raw, gd_alter_recip, gd_alter_sbit — modify a
       field in a dirfile

SYNOPSIS

       #include <getdata.h>

       int gd_alter_bit(DIRFILE *dirfile, const char *field_code, const char *in_field, gd_bit_t
              bitnum, gd_bit_t numbits);

       int gd_alter_carray(DIRFILE *dirfile, const char *field_code, gd_type_t const_type, size_t
              array_len);

       int gd_alter_clincom(DIRFILE *dirfile, const char *field_code, int n_fields, const char
              **in_fields, const double complex *cm, const double complex *cb);

       int gd_alter_const(DIRFILE *dirfile, const char *field_code, gd_type_t const_type);

       int gd_alter_cpolynom(DIRFILE *dirfile, const char *field_code, int poly_ord, const char
              *in_field, const double complex *ca);

       int gd_alter_crecip(DIRFILE *dirfile, const char *field_code, const char *in_field,
              complex double cdividend);

       int gd_alter_divide(DIRFILE *dirfile, const char *field_code, const char *in_field1, const
              char *in_field2);

       int gd_alter_lincom(DIRFILE *dirfile, const char *field_code, int n_fields, const char
              **in_fields, const double *m, const double *b);

       int gd_alter_linterp(DIRFILE *dirfile, const char *field_code, const char *in_field, const
              char *table, int rename_table);

       int gd_alter_multiply(DIRFILE *dirfile, const char *field_code, const char *in_field1,
              const char *in_field2);

       int gd_alter_phase(DIRFILE *dirfile, const char *field_code, const char *in_field,
              gd_shift_t shift);

       int gd_alter_polynom(DIRFILE *dirfile, const char *field_code, int poly_ord, const char
              *in_field, const double *ca);

       int gd_alter_raw(DIRFILE *dirfile, const char *field_code, gd_type_t data_type, gd_spf_t
              spf, int recode);

       int gd_alter_recip(DIRFILE *dirfile, const char *field_code, const char *in_field, double
              dividend);

       int gd_alter_sbit(DIRFILE *dirfile, const char *field_code, const char *in_field, gd_bit_t
              bitnum, gd_bit_t numbits);

DESCRIPTION

       These functions provide alternatives to using the gd_alter_entry(3) function to  modify  a
       field of the indicated type in the dirfile specified by dirfile.

       In  all  of these calls, field_code indicates the the field to be modified, which may be a
       regular field, or a metafield specified by its full (slashed) field code, but  should  not
       contain  a  representation  suffix.  The meaning and valid types of other arguments may be
       obtained from the get_entry(3) and dirfile-format(5) manual pages.  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.

       The   gd_alter_clincom()   and   gd_alter_cpolynom()   functions    are    identical    to
       gd_alter_lincom()  and  gd_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  gd_alter_lincom()  and
       gd_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, gd_alter_polynom()  and  gd_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, numbits, cdividend, or dividend  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 literal parameters.
       Field parameters which are scalar fields cannot be introduced with these functions.  To do
       that, use gd_alter_entry(3), gd_alter_spec(3) or gd_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  gd_alter_clincom(), gd_alter_crecip(), and
       gd_alter_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 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 indicated format specification 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  indicated  format  specification fragment does not
               support translating the binary file associated with a modified 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).

NOTES

       The       C89       GetData      API      provides      different      prototypes      for
       gd_alter_clincom(), gd_alter_cpolynom(), and gd_alter_crecip():

       #define GD_C89_API
       #include <getdata.h>

       int gd_alter_clincom(DIRFILE *dirfile, const char *field_code,
              int n_fields, const char **in_fields, const double *cm,
              const double *cb);

       int gd_alter_cpolynom(DIRFILE *dirfile, const char *field_code,
              int poly_ord, const char *in_fields, const double *ca);

       int gd_alter_crecip(DIRFILE *dirfile, const char *field_code,
              const char *in_field, double cdividend[2]);

       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.

SEE ALSO

       gd_alter_entry(3),  gd_alter_spec(3),  gd_error(3), gd_error_string(3), gd_malter_spec(3),
       gd_metaflush(3), gd_open(3), dirfile-format(5)