astGetColumnDataastGetColumnData
-
Retrieve all the data values stored in a column
- Description:
- This function
copies all data values from a named column into a supplied buffer
- Synopsis:
- void astGetColumnData( AstFitsTable
this, const char
column,
float fnull, double dnull, size_t mxsize,
void
coldata, int
nelem )
- Parameters:
-
this
-
Pointer to the FitsTableFitsTable.
-
column
-
The character string holding the name of the column. Trailing
spaces are ignored.
-
fnull
-
The value to return in
"coldata"
for any cells for which no value has been stored in the
FitsTable. Ignored if the column's data type is not
AST__FLOATTYPE. Supplying
AST__NANF
will cause a single precision IEEE NaN value to be used.
-
dnull
-
The value to return in
"coldata"
for any cells for which no value has been stored in the
FitsTable. Ignored if the column's data type is not
AST__DOUBLETYPE. Supplying AST__NAN will cause a double precision
IEEE NaN value to be used.
-
mxsize
-
The size of the
"coldata"
array, in bytes. The amount of memory needed to hold the data
from a column may be determined using
astColumnSizeastColumnSize.
If the supplied array is too small to hold all the column data,
trailing column values will be omitted from the returned array,
but no error will be reported.
-
coldata
-
A pointer to an
area of memory in which to return the data
values currently stored in the column. The values are stored in
row order. If the column holds non-scalar values, the elements
of each value are stored in "Fortran" order. No data type
conversion is performed - the data type of each returned value
is the data type associated with the column when the column was
added to the table. If the column holds strings, the returned
strings will be null terminated. Any excess room at the end of
the array will be left unchanged.
-
nelem
-
The number of elements returned in the
"coldata"
array. This is the product of the number of rows returned and
the number of elements in each column value.
- Notes:
- The "fnull" and "dnull" parameters
specify the value to be returned for any empty cells within columns
holding floating point values. For columns holding integer values,
the value returned for empty cells is the value returned by the
astColumNull function.
For columns holding string values, the ASCII NULL character is returned
for empty cells.