source: sasview/src/sas/sascalc/corfunc/transform_thread.py @ 2a54ba5

from sas.sascalc.data_util.calcthread import CalcThread
from sas.sascalc.dataloader.data_info import Data1D
from scipy.fftpack import dct
from scipy.integrate import trapz
import numpy as np
from time import sleep

class FourierThread(CalcThread):
    def __init__(self, raw_data, extrapolated_data, bg, extrap_fn=None,
        updatefn=None, completefn=None):
        CalcThread.__init__(self, updatefn=updatefn, completefn=completefn)
        self.data = raw_data
        self.background = bg
        self.extrapolation = extrapolated_data
        self.extrap_fn = extrap_fn

    def compute(self):
        qs = self.extrapolation.x
        iqs = self.extrapolation.y
        q = self.data.x
        background = self.background

        xs = np.pi*np.arange(len(qs),dtype=np.float32)/(q[1]-q[0])/len(qs)

        self.ready(delay=0.0)
        self.update(msg="Fourier transform in progress.")
        self.ready(delay=0.0)

        if self.isquit():
            return
        try:
            gamma1 = dct((iqs-background)*qs**2)
            gamma1 = gamma1 / gamma1.max()

            # gamma3(R) = 1/R int_{0}^{R} gamma1(x) dx
            # trapz uses the trapezium rule to calculate the integral
            gamma3 = [trapz(gamma1[:n], xs[:n])/xs[n-1] for n in range(1, len(xs+1))]
            gamma3 = np.array(gamma3)
        except Exception as e:
            import logging
            logger = logging.getLogger(__name__)
            logger.error(e)

            self.update(msg="Fourier transform failed.")
            self.complete(transforms=None)
            return
        if self.isquit():
            return
        self.update(msg="Fourier transform completed.")

        transform1 = Data1D(xs, gamma1)
        transform3 = Data1D(xs, gamma3)

        transforms = (transform1, transform3)

        self.complete(transforms=transforms)

class HilbertThread(CalcThread):
    def __init__(self, raw_data, extrapolated_data, bg, updatefn=None,
        completefn=None):
        CalcThread.__init__(self, updatefn=updatefn, completefn=completefn)
        self.data = raw_data
        self.background = bg
        self.extrapolation = extrapolated_data

    def compute(self):
        qs = self.extrapolation.x
        iqs = self.extrapolation.y
        q = self.data.x
        background = self.background

        self.ready(delay=0.0)
        self.update(msg="Starting Hilbert transform.")
        self.ready(delay=0.0)
        if self.isquit():
            return

        # TODO: Implement hilbert transform

        self.update(msg="Hilbert transform completed.")

        self.complete(transform=None)