1dirfile_alter_bit(3)                GETDATA               dirfile_alter_bit(3)
2
3
4

NAME

6       dirfile_alter_bit,      dirfile_alter_clincom,     dirfile_alter_const,
7       dirfile_alter_cpolynom,  dirfile_alter_lincom,   dirfile_alter_linterp,
8       dirfile_alter_multiply,   dirfile_alter_phase,   dirfile_alter_polynom,
9       dirfile_alter_raw, dirfile_alter_sbit — modify a field in a dirfile
10

SYNOPSIS

12       #include <getdata.h>
13
14       int dirfile_alter_bit(DIRFILE *dirfile, const char *field_code, const
15              char *in_field, gd_bit_t bitnum, gd_bit_t numbits);
16
17       int dirfile_alter_clincom(DIRFILE *dirfile, const char *field_code, int
18              n_fields, const char **in_fields, const double complex *cm,
19              const double complex *cb);
20
21       int dirfile_alter_const(DIRFILE *dirfile, const char *field_code,
22              gd_type_t const_type);
23
24       int dirfile_alter_cpolynom(DIRFILE *dirfile, const char *field_code,
25              int poly_ord, const char *in_field, const double complex *ca);
26
27       int dirfile_alter_lincom(DIRFILE *dirfile, const char *field_code, int
28              n_fields, const char **in_fields, const double *m, const double
29              *b);
30
31       int dirfile_alter_linterp(DIRFILE *dirfile, const char *field_code,
32              const char *in_field, const char *table, int rename_table);
33
34       int dirfile_alter_multiply(DIRFILE *dirfile, const char *field_code,
35              const char *in_field1, const char *in_field2);
36
37       int dirfile_alter_phase(DIRFILE *dirfile, const char *field_code, const
38              char *in_field, gd_shift_t shift);
39
40       int dirfile_alter_polynom(DIRFILE *dirfile, const char *field_code, int
41              poly_ord, const char *in_field, const double *ca);
42
43       int dirfile_alter_raw(DIRFILE *dirfile, const char *field_code,
44              gd_type_t data_type, gd_spf_t spf, int recode);
45
46       int dirfile_alter_sbit(DIRFILE *dirfile, const char *field_code, const
47              char *in_field, gd_bit_t bitnum, gd_bit_t numbits);
48

DESCRIPTION

50       These  functions  provide  alternatives  to using the dirfile_alter_en‐
51       try(3) function to modify a field of the indicated type in the  dirfile
52       specified by dirfile.
53
54       In  all  of these calls, field_code indicates the the field to be modi‐
55       fied, which may be a regular field, or a  metafield  specified  by  its
56       full  (slashed) field code, but should not contain a representtion suf‐
57       fix.  The meaning and valid types of other arguments  may  be  obtained
58       from the get_entry(3) and dirfile-format(5) manual pages.
59
60       The  dirfile_alter_clincom() and dirfile_alter_cpolynom() functions are
61       identical to dirfile_alter_lincom() and dirfile_alter_polynom(), except
62       they  take  complex  scalar  parameters, instead of purely real values.
63       This only matters for the input of new parameters; if the scalar param‐
64       eters  are  not changed (by passing NULL instead of a list of scalars),
65       the functions can be used interchangeably, regardless  of  whether  the
66       altered field has complex scalar parameters or not.
67
68       If  the  corresponding  parameters  are  to be changed, the dirfile_al‐
69       ter_lincom() and dirfile_alter_clincom()  functions  take  pointers  to
70       three  arrays  of  length  n_fields  containing  the  input field names
71       (in_fields), the gain factors (m or cm), and the  offset  terms  (b  or
72       cb).   Similarly,  dirfile_alter_polynom() and dirfile_alter_cpolynom()
73       take an array of length poly_ord + 1 containing the polynomial co-effi‐
74       cients (a or ca).
75
76       Some  field  parameters  have  special  values which indicate no change
77       should be made to the parameter.  Specifically, if any  of  the  string
78       parameters  or m, b, or a (cm, cb, or ca) are NULL, the old values will
79       be retained.  Similarly, if spf, n_fields, or numbits is  zero,  or  if
80       bitnum  is  -1,  or  if  data_type, or const_type are equal to GD_NULL,
81       these parameters will not be modified.
82
83       All field parameters introduced with this interface must contain numer‐
84       ical parameters.  Field parameters which are CONST cannot be introduced
85       with  these  functions.   To  do  that,   use   dirfile_alter_entry(3),
86       dirfile_alter_spec(3) or dirfile_malter_spec(3), as appropriate.
87
88       If  rename_table  is non-zero, the look-up table referenced by the LIN‐
89       TERP field will be renamed to the path given by table.   If  recode  is
90       non-zero,  the binary file associated with the RAW field will be re-en‐
91       coded to reflect the new field parameters.
92
93       See NOTES below for information on  using  dirfile_alter_clincom()  and
94       dirfile_alter_cpolynom() in the C89 GetData API.
95
96

RETURN VALUE

98       On  success, any of these functions returns zero.   On error, -1 is re‐
99       turned and the dirfile error is set to a non-zero error value.   Possi‐
100       ble error values are:
101
102       The gd_bit_t type is a signed 16-bit integer type.  The gd_shift_t type
103       is a signed 64-bit integer type.  The  gd_spf_t  type  is  an  unsigned
104       16-bit integer type.
105
106       GD_E_ACCMODE
107               The specified dirfile was opened read-only.
108
109       GD_E_ALLOC
110               The library was unable to allocate memory.
111
112       GD_E_BAD_CODE
113               The field specified by field_code was not found.
114
115       GD_E_BAD_DIRFILE
116               The supplied dirfile was invalid.
117
118       GD_E_BAD_ENTRY
119               One or more of the field parameters specified was invalid.
120
121       GD_E_BAD_FIELD_TYPE
122               The field specified by field_code was of the wrong type for the
123               function called.
124
125       GD_E_BAD_TYPE
126               The data_type or const_type argument was invalid.
127
128       GD_E_PROTECTED
129               The metadata of the fragment was protected from change.  Or,  a
130               request  to  translate  the  binary  file associated with a RAW
131               field was attempted, but the data of the fragment was  protect‐
132               ed.
133
134       GD_E_RAW_IO
135               An I/O error occurred while translating the binary file associ‐
136               ated with a modified RAW field, or an I/O error occurred  while
137               attempting to rename a LINTERP table file.
138
139       GD_E_UNKNOWN_ENCODING
140               The  encoding  scheme  of the specified format file fragment is
141               not known to the library.  As a result, the library was  unable
142               to  translate the binary file be associated with a modified RAW
143               field.
144
145       GD_E_UNSUPPORTED
146               The encoding scheme of the specified format file fragment  does
147               not support translating the empty binary file associated with a
148               modified RAW field.
149
150       The dirfile error may be retrieved by calling get_error(3).  A descrip‐
151       tive error string for the last error encountered can be obtained from a
152       call to get_error_string(3).
153
154

NOTES

156       The C89 GetData  API  provides  different  prototypes  for  dirfile_al‐
157       ter_clincom() and dirfile_alter_cpolynom():
158
159       #define GETDATA_C89_API
160       #include <getdata.h>
161
162       int dirfile_alter_clincom(DIRFILE *dirfile, const char *field_code,
163              int n_fields, const char **in_fields, const double *cm,
164              const double *cb);
165
166       int dirfile_alter_cpolynom(DIRFILE *dirfile, const char *field_code,
167              int poly_ord, const char *in_fields, const double *ca);
168
169       In  this  case,  the  array pointers passed as cm, cb or ca should have
170       twice as many (purely real) elements, consisting  of  alternating  real
171       and imaginary parts for the complex data.  For example, ca[0] should be
172       the real part of the first co-efficient, ca[1] the  imaginary  part  of
173       the first co-efficient, ca[2] the real part of the second co-efficient,
174       ca[3] the imaginary part of the second co-efficient, and so on.
175
176

SEE ALSO

178       dirfile_alter_entry(3), dirfile_alter_spec(3),  dirfile_malter_spec(3),
179       dirfile_metaflush(3),     dirfile_open(3),     get_error(3),    get_er‐
180       ror_string(3), dirfile-format(5)
181
182
183
184Version 0.6.0                   2 November 2009           dirfile_alter_bit(3)
Impressum