.\" gd_madd_bit.3.  The gd_madd_bit man page.
.\"
.\" Copyright (C) 2008, 2009, 2010, 2012, 2013 D. V. Wiebe
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.TH gd_madd_bit 3 "30 September 2013" "Version 0.9.0" "GETDATA"
.SH NAME
gd_madd_bit, gd_madd_carray, gd_madd_clincom, gd_madd_const, gd_madd_cpolynom,
gd_madd_crecip, gd_madd_divide, gd_madd_lincom, gd_madd_linterp,
gd_madd_multiply, gd_madd_phase, gd_madd_polynom, gd_madd_recip, gd_madd_sbit,
gd_madd_string
\(em add a field to a dirfile
.SH SYNOPSIS
.B #include <getdata.h>
.HP
.nh
.ad l
.BI "int gd_madd_bit(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "const char *" in_field ", int " bitnum ", int " numbits );
.HP
.BI "int gd_madd_carray(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "gd_type_t " const_type ", size_t " array_len ", gd_type_t " data_type ,
.BI "void *" value );
.HP
.BI "int gd_madd_clincom(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", int " n_fields ", const char **" in_fields ,
.BI "const double complex *" cm ", const double complex *" cb );
.HP
.BI "int gd_madd_const(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "gd_type_t " const_type ", gd_type_t " data_type ", void *" value );
.HP
.BI "int gd_madd_cpolynom(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", int " poly_ord ", const char *" in_field ,
.BI "const double complex *" ca );
.HP
.BI "int gd_madd_crecip(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", const char *" in_field ,
.BI "double complex " cdividend ", int " fragment_index );
.HP
.BI "int gd_madd_divide(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI " const char *" in_field1 ", const char *" in_field2 );
.HP
.BI "int gd_madd_lincom(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", int " n_fields ", const char **" in_fields ,
.BI "const double *" m ", const double *" b );
.HP
.BI "int gd_madd_linterp(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "const char *" in_field ", const char *" table );
.HP
.BI "int gd_madd_mplex(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "const char *" in_field ", const char *" count_field ,
.BI "int " count_val ", int " period );
.HP
.BI "int gd_madd_multiply(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI " const char *" in_field1 ", const char *" in_field2 );
.HP
.BI "int gd_madd_polynom(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", int " poly_ord ", const char *" in_field ,
.BI "const double *" a );
.HP
.BI "int gd_madd_phase(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "const char *" in_field ", gd_shift_t " shift );
.HP
.BI "int gd_madd_recip(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", const char *" in_field ,
.BI "double " dividend ", int " fragment_index );
.HP
.BI "int gd_madd_sbit(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "const char *" in_field ", int " bitnum ", int " numbits );
.HP
.BI "int gd_madd_string(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", const char *" value );
.HP
.BI "int gd_madd_window(DIRFILE *" dirfile ,
.BI "const char *" parent ", const char *" field_name ,
.BI "const char *" in_field ", const char *" check_field ", gd_windop_t"
.IB windop ", gd_triplet_t " threshold );
.hy
.ad n
.SH DESCRIPTION
These functions add a new metafield of the indicated type under the parent field
given by
.I parent
in the dirfile specified by
.IR dirfile .
.PP
In all of these calls,
.I field_name
indicates the name of the field to be added.  It should not be the full
.IB <parent-field> / <meta-field>
field code.  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_madd_clincom ()
and
.BR gd_madd_cpolynom ()
functions are identical to
.BR gd_madd_lincom ()
and
.BR gd_madd_polynom (),
except they take complex scalar parameters, instead of purely real values.

The
.BR gd_madd_lincom ()
and
.BR gd_madd_clincom ()
functions take 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_madd_polynom ()
and
.BR gd_madd_cpolynom ()
take an array of length
.I poly_ord
+ 1
containing the polynomial co-efficients
.RI ( a " or " ca ).

The
.BR gd_madd_string (),\~ gd_madd_carray ,
and
.BR gd_madd_const ()
functions both add the field and set the value of the field to
.IR value .
For
.BR gd_madd_const ()
and
.BR gd_madd_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
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
.BR gd_madd (3)
or
.BR gd_madd_spec (3).
See
.BR gd_add_bit (3),
&c. for an alternate way of adding metafields with explicit parameters.

See
.B NOTES
below for information on using
.BR gd_madd_clincom "(), " gd_madd_cpolynom (),
and 
.BR gd_madd_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
argument contained invalid characters. Alternately, the
.I parent
field code was not found, or was already a metafield.
.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_TYPE
The
.IR data_type " or " const_type
argument provided to
.BR gd_madd_const ()
or
.BR gd_madd_carray ()
was invalid.
.TP
.B GD_E_DUPLICATE
The
.IR field_name
provided duplicated that of an already existing field.
.TP
.B GD_E_PROTECTED
The metadata of the fragment was protected from change.
.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_madd_clincom (),\~ gd_madd_cpolynom (),
and
.BR gd_madd_crecip ():
.PP
.B #define GD_C89_API
.br
.B #include <getdata.h>
.HP
.nh
.ad l
.BI "int gd_madd_clincom(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", int " n_fields ", const char **" in_fields ,
.BI "const double *" cm ", const double *" cb );
.HP
.BI "int gd_madd_cpolynom(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", int " poly_ord ", const char *" in_field ,
.BI "const double *" ca );
.HP
.BI "int gd_madd_crecip(DIRFILE *" dirfile ", const char *" parent ,
.BI "const char *" field_name ", const char *" in_field ,
.BI "double " cdividend\fR[2] ", 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_madd_clincom ()
and
.BR gd_madd_cpolynom (),
these are simply different (but equivalent) declarations of the C99 function
entry point.  For
.BR gd_madd_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_madd_crecip ()
is always available, and may be accessed as
.BR gd_madd_crecip89 (),
with the C89 prototype, in both the C99 and C89 APIs.

.SH SEE ALSO
.BR gd_add_bit (3),
.BR gd_add_const (3),
.BR gd_add_divide (3),
.BR gd_add_lincom (3),
.BR gd_add_linterp (3),
.BR gd_add_mplex (3),
.BR gd_add_multiply (3),
.BR gd_add_phase (3),
.BR gd_add_polynom (3),
.BR gd_add_recip (3),
.BR gd_add_string (3),
.BR gd_add_windop (3),
.BR gd_entry (3),
.BR gd_error (3),
.BR gd_error_string (3),
.BR gd_madd (3),
.BR gd_madd_spec (3),
.BR gd_metaflush (3),
.BR gd_open (3),
.BR dirfile-format (5)