ifftfreq_shifted

PlasmaCalcs.tools.fft_tools.array_fft.ifftfreq_shifted(N, df=None, *, rad=False, x0=0, ds=None, float_rounding=True)

returns the shifted positions corresponding to the inverse fft of an array of length N.

df: None or number

spacing between elements of array (in frequency-space).

None –> use ds to determine position coordinates instead.

rad: bool

whether to interpret frequency-spacing (df) like it is “in radians”,

dividing it by 2 * pi before converting to position-space.

x0: None or number

if provided, add value to result such that result[0] == x0.

(This corresponds to altering position-space coordinates by a constant offset.)

ds: None or number

if provided, actually use this as position diff, instead of determining it from d & rad.

float_rounding: bool

if True, round ds to a more-likely-to-be-input float.

e.g. 0.20000000001 –> float(0.2); 0.399999999 –> float(0.4); 0.123456781234 –> unchanged.