The forward transform and backward transform are each associated with a scale factor
σof its own having the default value of 1. You can specify the scale factors using one or both of the configuration parameters
DFTI_BACKWARD_SCALE. For example, for a one-dimensional transform of length
n, you can use the default scale of 1 for the forward transform and set the scale factor for the backward transform to be 1/
n, thus making the backward transform the inverse of the forward transform.
Set the scale factor configuration parameter using a real floating-point data type of the same precision as the value for
For inquiry of the scale factor with the
config_valparameter must have the same floating-point precision as the descriptor.