Implicit Data Type Conversion

The CFITSIO routines that read and write numerical data can perform implicit data type conversion. This means that the data type of the variable or array in the program does not need to be the same as the data type of the value in the FITS file. Data type conversion is supported for numerical data types when reading a FITS header keyword value and when reading or writing values in the primary array or a table column. CFITSIO returns status = NUM_OVERFLOW if the converted data value exceeds the range of the output data type. Implicit data type conversion is not supported for string, logical, complex, or double complex data types.