Template Function helpme::findGridSize

Function Documentation

template<typename T>
int helpme::findGridSize(T inputSize, const std::initializer_list<T> &requiredDivisors)

findGridSize FFTW likes to have transformations with dimensions of the form 

  a  b  c  d   e   f
 2  3  5  7  11  13
where a,b,c and d are general and e+f is either 0 or 1. MKL has similar demands:

https://software.intel.com/en-us/articles/fft-length-and-layout-advisor/ http://www.fftw.org/fftw3_doc/Real_002ddata-DFTs.html

This routine will compute the next largest grid size subject to the constraint that the resulting size is a multiple of a given factor.

Parameters:

  • inputSize – the minimum size of the grid.

  • requiredDivisors – list of values that must be a factor of the output grid size.

Returns:

the adjusted grid size.