scipy.fft.

fhtoffset#

scipy.fft.fhtoffset(dln, mu, initial=0.0, bias=0.0)[source]#

Return optimal offset for a fast Hankel transform.

Returns an offset close to initial that fulfils the low-ringing condition of [1] for the fast Hankel transform fht with logarithmic spacing dln, order mu and bias bias.

Parameters:

dlnfloat: Uniform logarithmic spacing of the transform.
mufloat: Order of the Hankel transform, any positive or negative real number.
initialfloat, optional: Initial value for the offset. Returns the closest value that fulfils the low-ringing condition.
biasfloat, optional: Exponent of power law bias, any positive or negative real number.

Returns:

offsetfloat: Optimal offset of the uniform logarithmic spacing of the transform that fulfils a low-ringing condition.

See also

fht: Definition of the fast Hankel transform.

References

[1]

Hamilton A. J. S., 2000, MNRAS, 312, 257 (astro-ph/9905191)

Examples

>>> from scipy.fft import fhtoffset
>>> dln = 0.1
>>> mu = 2.0
>>> initial = 0.5
>>> bias = 0.0
>>> offset = fhtoffset(dln, mu, initial, bias)
>>> offset
0.5454581477676637