nmrglue.process.proc_lp.lp_1d

nmrglue.process.proc_lp.lp_1d(trace, pred=1, slice=slice(None, None, None), order=8, mode='f', append='after', bad_roots='auto', fix_mode='on', mirror=None, method='svd')

Linear Prediction extrapolation of 1D data.

Parameter:

• trace 1D trace of data, the FID.

• pred Number of points to predict.

• slice slice object selecting region of slice to use in LP equation.

• order Prediction order (Number of LP coefficients)

• mode Mode to generate LP filter (f-forward,b-backward,

  fb-“forward-backward”,bf-“backward-forward”)

• extend Extend trace before or after trace, (“before” or “after”).

• bad_roots Type of roots which are bad and should be stabilized,

  either those with “incr” or “decr” signals, set to None for no root stabilizing. Default of “auto” set root fixing based on LP mode. (mode==”f” or “fb” -> “incr”, mode==”b” or “bf” -> “decr”)

• fix_mode Method used to stabilize bad roots, “on” to move the roots

  onto the unit circle, “reflect” to reflect bad roots across the unit circle

• mirror None to process trace as provided, ‘0’ or ‘180’ forms a mirror

  image of the sliced trace to calculate the LP filter. ‘0’ should be used with data with no delay, ‘180’ with data with an initial half-point delay.

• method Method to use to calculate the LP filter, choose from

  ‘svd’,’qr’,’choleskey’ or ‘tls’.

Notes:

In forward-backward or backward-forward mode root stabilizing is done on both sets of signal roots as calculated in the first mode direction. After averaging the coefficient the roots are again stabilized.

When the append parameter does not match the LP mode, for example if a backward linear prediction (mode=’b’) is used to predict points after the trace (append=’after’), any root fixing is done before reversing the filter.