Ejemplo n.º 1
0
    def _vana_correct(self):
        """
        creates the corrected workspace
        """
        wslist = []
        # 1. normalize Vanadium and Background
        vana_normws = api.mtd[self.vanaws.getName() + '_NORM']
        bkg_normws = api.mtd[self.bkgws.getName() + '_NORM']
        _vana_norm_ = api.Divide(self.vanaws, vana_normws)
        wslist.append(_vana_norm_.getName())
        _bkg_norm_ = api.Divide(self.bkgws, bkg_normws)
        wslist.append(_bkg_norm_.getName())
        # 2. substract background from Vanadium
        _vana_bg_ = _vana_norm_ - _bkg_norm_
        wslist.append(_vana_bg_.getName())
        # check negative values, throw exception
        arr = np.array(_vana_bg_.extractY()).flatten()
        neg_values = np.where(arr < 0)[0]
        if len(neg_values):
            mlzutils.cleanup(wslist)
            message = "Background " + self.bkgws.getName() + " is higher than Vanadium " + \
                self.vanaws.getName() + " signal!"
            self.log().error(message)
            raise RuntimeError(message)

        # 3. calculate correction coefficients
        _vana_mean_ws_ = self._vana_mean(_vana_bg_)
        if not _vana_mean_ws_:
            mlzutils.cleanup(wslist)
            return None
        if not self.vana_mean_name:
            wslist.append(_vana_mean_ws_.getName())
        _coef_ws_ = api.Divide(LHSWorkspace=_vana_bg_, RHSWorkspace=_vana_mean_ws_, WarnOnZeroDivide=True)
        wslist.append(_coef_ws_.getName())
        # 4. correct raw data (not normalized!)
        api.Divide(LHSWorkspace=self.dataws, RHSWorkspace=_coef_ws_, WarnOnZeroDivide=True,
                   OutputWorkspace=self.outws_name)
        outws = api.mtd[self.outws_name]
        # cleanup
        mlzutils.cleanup(wslist)
        return outws
Ejemplo n.º 2
0
    def _fr_correction(self):
        """
        applies flipping ratio correction
        creates the corrected workspaces
        """
        wslist = []
        # 1. normalize NiCr and Background
        sf_nicr_normws = api.AnalysisDataService.retrieve(self.input_workspaces['SF_NiCr'] + '_NORM')
        sf_nicr = api.AnalysisDataService.retrieve(self.input_workspaces['SF_NiCr'])
        _sf_nicr_norm_ = api.Divide(sf_nicr, sf_nicr_normws)
        wslist.append(_sf_nicr_norm_.getName())

        nsf_nicr_normws = api.AnalysisDataService.retrieve(self.input_workspaces['NSF_NiCr'] + '_NORM')
        nsf_nicr = api.AnalysisDataService.retrieve(self.input_workspaces['NSF_NiCr'])
        _nsf_nicr_norm_ = api.Divide(nsf_nicr, nsf_nicr_normws)
        wslist.append(_nsf_nicr_norm_.getName())

        sf_bkgr_normws = api.AnalysisDataService.retrieve(self.input_workspaces['SF_Background'] + '_NORM')
        sf_bkgr = api.AnalysisDataService.retrieve(self.input_workspaces['SF_Background'])
        _sf_bkgr_norm_ = api.Divide(sf_bkgr, sf_bkgr_normws)
        wslist.append(_sf_bkgr_norm_.getName())

        nsf_bkgr_normws = api.AnalysisDataService.retrieve(self.input_workspaces['NSF_Background'] + '_NORM')
        nsf_bkgr = api.AnalysisDataService.retrieve(self.input_workspaces['NSF_Background'])
        _nsf_bkgr_norm_ = api.Divide(nsf_bkgr, nsf_bkgr_normws)
        wslist.append(_nsf_bkgr_norm_.getName())

        # 2. subtract background from NiCr
        _sf_nicr_bg_ = _sf_nicr_norm_ - _sf_bkgr_norm_
        wslist.append(_sf_nicr_bg_.getName())
        _nsf_nicr_bg_ = _nsf_nicr_norm_ - _nsf_bkgr_norm_
        wslist.append(_nsf_nicr_bg_.getName())
        # check negative values, throw exception
        sf_arr = np.array(_sf_nicr_bg_.extractY()).flatten()
        nsf_arr = np.array(_nsf_nicr_bg_.extractY()).flatten()
        sf_neg_values = np.where(sf_arr < 0)[0]
        nsf_neg_values = np.where(nsf_arr < 0)[0]
        if len(sf_neg_values) or len(nsf_neg_values):
            mlzutils.cleanup(wslist)
            message = "Background is higher than NiCr signal!"
            self.log().error(message)
            raise RuntimeError(message)

        # 3. calculate correction coefficients
        _coef_ws_ = api.Divide(LHSWorkspace=_nsf_nicr_bg_, RHSWorkspace=_sf_nicr_bg_, WarnOnZeroDivide=True)
        wslist.append(_coef_ws_.getName())
        # 4. apply correction raw data (not normalized!)
        sf_data_ws = api.AnalysisDataService.retrieve(self.input_workspaces['SF_Data'])
        nsf_data_ws = api.AnalysisDataService.retrieve(self.input_workspaces['NSF_Data'])
        # NSF_corr[i] = NSF[i] - SF[i]/c[i]
        _tmp_ws_ = api.Divide(LHSWorkspace=sf_data_ws, RHSWorkspace=_coef_ws_, WarnOnZeroDivide=True)
        _tmp_ws_.setYUnit(nsf_data_ws.YUnit())
        api.Minus(LHSWorkspace=nsf_data_ws, RHSWorkspace=_tmp_ws_, OutputWorkspace=self.nsf_outws_name)
        nsf_outws = api.AnalysisDataService.retrieve(self.nsf_outws_name)
        api.DeleteWorkspace(_tmp_ws_)
        # SF_corr[i] = SF[i] - NSF[i]/c[i]
        _tmp_ws_ = api.Divide(LHSWorkspace=nsf_data_ws, RHSWorkspace=_coef_ws_, WarnOnZeroDivide=True)
        _tmp_ws_.setYUnit(sf_data_ws.YUnit())
        api.Minus(LHSWorkspace=sf_data_ws, RHSWorkspace=_tmp_ws_, OutputWorkspace=self.sf_outws_name)
        sf_outws = api.AnalysisDataService.retrieve(self.sf_outws_name)
        api.DeleteWorkspace(_tmp_ws_)

        # 5. Apply correction for a double spin-flip scattering
        if self.dfr > 1e-7:
            _tmp_ws_ = sf_outws * self.dfr
            _tmp_ws_.setYUnit(nsf_outws.YUnit())
            wslist.append(_tmp_ws_.getName())
            # NSF_corr[i] = NSF_prev_corr[i] - SF_prev_corr*dfr, SF_corr = SF_prev_corr
            api.Minus(LHSWorkspace=nsf_outws, RHSWorkspace=_tmp_ws_, OutputWorkspace=self.nsf_outws_name)

        # cleanup
        mlzutils.cleanup(wslist)
        return