Fast C-routines to calculate distance arrays from coordinate arrays.
Calculate all distances d_ij between the coordinates ref[i] and conf[j] in the numpy arrays ref and conf. If an orthorhombic box is supplied then a minimum image convention is used before calculating distances.
If a 2D numpy array of dtype numpy.float64 with the shape (len(ref), len(conf)) is provided in result then this preallocated array is filled. This can speed up calculations.
Calculate all distances d_ij between atoms i and j in the reference coordinates ref for all N coordinates. Other options as in distance_array().
If a 1D numpy array of dtype numpy.float64 with N*(N-1)/2 elements is provided in result then this preallocated array is filled. This can speed up calculations.