.\" gd_add_bit.3.  The gd_add_bit man page.
.\"
.\" Copyright (C) 2008, 2009, 2010, 2012, 2013, 2014 D. V. Wiebe
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.TH gd_add_bit 3 "16 October 2014" "Version 0.9.0" "GETDATA"
.SH NAME
gd_add_bit, gd_add_carray gd_add_clincom, gd_add_const, gd_add_cpolynom,
gd_add_crecip, gd_add_divide, gd_add_lincom, gd_add_linterp, gd_add_multiply,
gd_add_phase, gd_add_polynom, gd_add_raw, gd_add_recip, gd_add_sbit,
gd_add_string
\(em add a field to a dirfile
.SH SYNOPSIS
.B #include <getdata.h>
.HP
.nh
.ad l
.BI "int gd_add_bit(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", int " bitnum ", int " numbits ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_carray(DIRFILE *" dirfile ", const char *" field_name ,
.BI "gd_type_t " const_type ", size_t " array_len ", gd_type_t " data_type ,
.BI "void *" value ", int " fragment_index );
.HP
.BI "int gd_add_clincom(DIRFILE *" dirfile ", const char *" field_name ,
.BI "int " n_fields ", const char **" in_fields ", const double complex *" cm ,
.BI "const double complex *" cb ", int " fragment_index );
.HP
.BI "int gd_add_const(DIRFILE *" dirfile ", const char *" field_name ,
.BI "gd_type_t " const_type ", gd_type_t " data_type ", void *" value ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_cpolynom(DIRFILE *" dirfile ", const char *" field_name ,
.BI "int " poly_ord ", const char *" in_fields ", const double complex *" ca ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_crecip(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", double complex " cdividend ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_divide(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field1 ", const char *" in_field2 ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_lincom(DIRFILE *" dirfile ", const char *" field_name ,
.BI "int " n_fields ", const char **" in_fields ", const double *" m ,
.BI "const double *" b ", int " fragment_index );
.HP
.BI "int gd_add_linterp(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", const char *" table ", int " fragment_index );
.HP
.BI "int gd_add_mplex(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", const char *" count_field ,
.BI "int " count_val ", int " period ", int " fragment_index );
.HP
.BI "int gd_add_multiply(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field1 ", const char *" in_field2 ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_phase(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", gd_shift_t " shift ", int " fragment_index );
.HP
.BI "int gd_add_polynom(DIRFILE *" dirfile ", const char *" field_name ,
.BI "int " poly_ord ", const char *" in_fields ", const double *" a ,
.BI int " fragment_index );
.HP
.BI "int gd_add_raw(DIRFILE *" dirfile ", const char *" field_name ,
.BI "gd_type_t " data_type ", unsigned int " spf ", int " fragment_index );
.HP
.BI "int gd_add_recip(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", double " dividend ", int " fragment_index );
.HP
.BI "int gd_add_sbit(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", int " bitnum ", int " numbits ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_string(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" value ", int " fragment_index );
.HP
.BI "int gd_add_window(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", const char *" check_field ", gd_windop_t"
.IB windop ", gd_triplet_t " threshold ", int " fragment_index );
.hy
.ad n
.SH DESCRIPTION
These functions provide alternatives to using the
.BR gd_add (3)
or
.BR gd_add_spec (3)
functions to add a new field of the indicated type to the dirfile specified by
.IR dirfile .
.PP
In all of these calls,
.I field_name
indicates the name of the field to be added.  Further,
.I 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
.BR gd_fragmentname (3).)
The meaning and valid types of other arguments may be obtained from the
.BR gd_entry (3)
and
.BR dirfile-format (5)
manual pages.

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

The
.BR gd_add_lincom ()
and
.BR gd_add_clincom ()
functions takes pointers to three arrays of length
.I n_fields
containing the input field names
.RI ( in_fields ),
the gain factors
.RI ( m " or " cm ),
and the offset terms
.RI ( b " or " cb ).
Similarly,
.BR gd_add_polynom ()
and
.BR gd_add_cpolynom ()
take an array of length
.I poly_ord
+ 1
containing the polynomial co-efficients
.RI ( a " or " ca ).

The
.BR gd_add_string (),
.BR gd_add_carry (),
and
.BR gd_add_const ()
functions add the field and set the value of the field to
.IR value .
For
.BR gd_add_const ()
and
.BR gd_add_carray (),
the
.I const_type
argument specifies the storage type for the const, while
.I data_type
specifies the data type of the value pointed to by
.IR value .

The
.B gd_shift_t
type is a signed 64-bit integer type.  The
.B gd_triplet_t
type is defined as:
.PP
.in +4n
.nf
.fam C
typedef union {
  gd_int64_t i;
  gd_uint64_t u;
  double r;
} gd_triplet_t;
.fam
.fi
.in
.PP
Which element of this
.B gd_triplet_t
union to set depends on the operator selected for the
.B WINDOW
field.  See
.BR gd_entry (3)
for details.
.PP
A metafield may be added to the dirfile either by calling these functions with
.I field_name
containing the fully formed
.IB <parent-field> / <meta-field>
field code, or else by using the corresponding
.BR gd_madd_ ...()
function (see
.BR gd_madd_bit (3),
&c.) When adding a metafield with these functions,
.I fragment_index
is ignored and GetData will add the new metafield to the same format
specification fragment in which the parent field is defined.  If the specified
parent field name is an alias, the canonical name of the field will be
substituted.

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
.BR gd_add (3)
or
.BR gd_add_spec (3).

See
.B NOTES
below for information on using
.BR gd_add_clincom ()", " gd_add_cpolynom (),
and
.BR gd_add_crecip ()
in the C89 GetData API.

.SH 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:
.TP 8
.B GD_E_ACCMODE
The specified dirfile was opened read-only.
.TP
.B GD_E_ALLOC
The library was unable to allocate memory.
.TP
.B GD_E_BAD_CODE
The
.IR field_name
contained invalid characters; or it or an input field did not contain the
affected fragment's prefix or suffix.
.TP
.B GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
.TP
.B GD_E_BAD_ENTRY
One or more of the field parameters specified was invalid.
.TP
.B GD_E_BAD_INDEX
The
.IR fragment_index
argument was out of range.
.TP
.B GD_E_BAD_TYPE
The
.IR data_type " or " const_type
argument provided to
.BR gd_add_raw "()  or " gd_add_const (),
was invalid.
.TP
.B GD_E_DUPLICATE
The
.IR field_name
provided duplicated that of an already existing field.
.TP
.B 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.
.TP
.B GD_E_IO
.RB ( gd_add_raw ()
only)  An I/O error occurred while creating an empty binary file to be
associated with a newly added
.B RAW
field.
.TP
.B GD_E_PROTECTED
The metadata of the fragment was protected from change.  Or, the creation of a
.B RAW
field was attempted and the data of the fragment was protected.
.TP
.B GD_E_UNKNOWN_ENCODING
.RB ( gd_add_raw ()
only) 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
.B RAW
field.
.TP
.B GD_E_UNSUPPORTED
.RB ( gd_add_raw ()
only) The encoding scheme of the indicated format specification fragment does
not support creating an empty binary file to be associated with a newly added
.B RAW
field.
.PP
The dirfile error may be retrieved by calling
.BR gd_error (3).
A descriptive error string for the last error encountered can be obtained from
a call to
.BR gd_error_string (3).

.SH NOTES
The C89 GetData API provides different prototypes for
.BR gd_add_clincom "(), " gd_add_cpolynom (),
and
.BR gd_add_crecip ():
.PP
.nf
.B #define GD_C89_API
.br
.B #include <getdata.h>
.fi
.HP
.nh
.ad l
.BI "int gd_add_clincom(DIRFILE *" dirfile ", const char *" field_name ,
.BI "int " n_fields ", const char **" in_fields ", const double *" cm ,
.BI "const double *" cb ", int " fragment_index );
.HP
.BI "int gd_add_cpolynom(DIRFILE *" dirfile ", const char *" field_name ,
.BI "int " poly_ord ", const char *" in_fields ", const double *" ca ,
.BI "int " fragment_index );
.HP
.BI "int gd_add_crecip(DIRFILE *" dirfile ", const char *" field_name ,
.BI "const char *" in_field ", const double " cdividend\fR[2] ,
.BI "int " fragment_index );
.hy
.ad n
.PP
In this case, the array pointers passed as
.IR cm ", " cb
or
.IR ca
should have twice as many (purely real) elements, consisting of alternating
real and imaginary parts for the complex data.  That is, for example,
.IR ca [0]
should be the real part of the first co-efficient,
.IR ca [1]
the imaginary part of the first co-efficient,
.IR ca [2]
the real part of the second co-efficient,
.IR ca [3]
the imaginary part of the second co-efficient, and so on.  Similarly, the
.I cdividend
parameter becomes a double precision array of length two.
.PP
For
.BR gd_add_clincom ()
and
.BR gd_add_cpolynom (),
these are simply different (but equivalent) declarations of the C99 function
entry point.  For
.BR gd_add_crecip (),
however, a different entry point is needed (since the
.I cdividend
parameter is passed by reference instead of by value).  In the interests of
portability, the C89 version of
.BR gd_add_crecip ()
is always available, and may be accessed as
.BR gd_add_crecip89 (),
with the C89 prototype, in both the C99 and C89 APIs.

.SH SEE ALSO
.BR gd_add (3),
.BR gd_add_spec (3),
.BR gd_entry (3),
.BR gd_error (3),
.BR gd_error_string (3),
.BR gd_madd_bit (3),
.BR gd_madd_carray (3),
.BR gd_madd_const (3),
.BR gd_madd_divide (3),
.BR gd_madd_lincom (3),
.BR gd_madd_linterp (3),
.BR gd_madd_mplex (3),
.BR gd_madd_multiply (3),
.BR gd_madd_phase (3),
.BR gd_madd_polynom (3),
.BR gd_madd_recip (3),
.BR gd_madd_sbit (3),
.BR gd_madd_string (3),
.BR gd_madd_window (3),
.BR gd_metaflush (3),
.BR gd_open (3),
.BR dirfile-format (5)