Source code for sas.dataloader.readers.abs_reader

"""
"""
#####################################################################
#This software was developed by the University of Tennessee as part of the
#Distributed Data Analysis of Neutron Scattering Experiments (DANSE)
#project funded by the US National Science Foundation.
#See the license text in license.txt
#copyright 2008, University of Tennessee
######################################################################

import numpy
import os
from sas.dataloader.data_info import Data1D
from sas.dataloader.data_info import Detector

has_converter = True
try:
    from sas.data_util.nxsunit import Converter
except:
    has_converter = False
    
    
[docs]class Reader: """ Class to load IGOR reduced .ABS files """ ## File type type_name = "IGOR 1D" ## Wildcards type = ["IGOR 1D files (*.abs)|*.abs"] ## List of allowed extensions ext = ['.abs', '.ABS']
[docs] def read(self, path): """ Load data file. :param path: file path :return: Data1D object, or None :raise RuntimeError: when the file can't be opened :raise ValueError: when the length of the data vectors are inconsistent """ if os.path.isfile(path): basename = os.path.basename(path) root, extension = os.path.splitext(basename) if extension.lower() in self.ext: try: input_f = open(path,'r') except: raise RuntimeError, "abs_reader: cannot open %s" % path buff = input_f.read() lines = buff.split('\n') x = numpy.zeros(0) y = numpy.zeros(0) dy = numpy.zeros(0) dx = numpy.zeros(0) output = Data1D(x, y, dy=dy, dx=dx) detector = Detector() output.detector.append(detector) output.filename = basename is_info = False is_center = False is_data_started = False data_conv_q = None data_conv_i = None if has_converter == True and output.x_unit != '1/A': data_conv_q = Converter('1/A') # Test it data_conv_q(1.0, output.x_unit) if has_converter == True and output.y_unit != '1/cm': data_conv_i = Converter('1/cm') # Test it data_conv_i(1.0, output.y_unit) for line in lines: # Information line 1 if is_info == True: is_info = False line_toks = line.split() # Wavelength in Angstrom try: value = float(line_toks[1]) if has_converter == True and \ output.source.wavelength_unit != 'A': conv = Converter('A') output.source.wavelength = conv(value, units=output.source.wavelength_unit) else: output.source.wavelength = value except: #goes to ASC reader msg = "abs_reader: cannot open %s" % path raise RuntimeError, msg # Distance in meters try: value = float(line_toks[3]) if has_converter == True and \ detector.distance_unit != 'm': conv = Converter('m') detector.distance = conv(value, units=detector.distance_unit) else: detector.distance = value except: #goes to ASC reader msg = "abs_reader: cannot open %s" % path raise RuntimeError, msg # Transmission try: output.sample.transmission = float(line_toks[4]) except: # Transmission is not a mandatory entry pass # Thickness in mm try: value = float(line_toks[5]) if has_converter == True and \ output.sample.thickness_unit != 'cm': conv = Converter('cm') output.sample.thickness = conv(value, units=output.sample.thickness_unit) else: output.sample.thickness = value except: # Thickness is not a mandatory entry pass #MON CNT LAMBDA DET ANG DET DIST TRANS THICK # AVE STEP if line.count("LAMBDA") > 0: is_info = True # Find center info line if is_center == True: is_center = False line_toks = line.split() # Center in bin number center_x = float(line_toks[0]) center_y = float(line_toks[1]) # Bin size if has_converter == True and \ detector.pixel_size_unit != 'mm': conv = Converter('mm') detector.pixel_size.x = conv(5.0, units=detector.pixel_size_unit) detector.pixel_size.y = conv(5.0, units=detector.pixel_size_unit) else: detector.pixel_size.x = 5.0 detector.pixel_size.y = 5.0 # Store beam center in distance units # Det 640 x 640 mm if has_converter == True and \ detector.beam_center_unit != 'mm': conv = Converter('mm') detector.beam_center.x = conv(center_x * 5.0, units=detector.beam_center_unit) detector.beam_center.y = conv(center_y * 5.0, units=detector.beam_center_unit) else: detector.beam_center.x = center_x * 5.0 detector.beam_center.y = center_y * 5.0 # Detector type try: detector.name = line_toks[7] except: # Detector name is not a mandatory entry pass #BCENT(X,Y) A1(mm) A2(mm) A1A2DIST(m) DL/L # BSTOP(mm) DET_TYP if line.count("BCENT") > 0: is_center = True # Parse the data if is_data_started == True: toks = line.split() try: _x = float(toks[0]) _y = float(toks[1]) _dy = float(toks[2]) _dx = float(toks[3]) if data_conv_q is not None: _x = data_conv_q(_x, units=output.x_unit) _dx = data_conv_i(_dx, units=output.x_unit) if data_conv_i is not None: _y = data_conv_i(_y, units=output.y_unit) _dy = data_conv_i(_dy, units=output.y_unit) x = numpy.append(x, _x) y = numpy.append(y, _y) dy = numpy.append(dy, _dy) dx = numpy.append(dx, _dx) except: # Could not read this data line. If we are here # it is because we are in the data section. Just # skip it. pass #The 6 columns are | Q (1/A) | I(Q) (1/cm) | std. dev. # I(Q) (1/cm) | sigmaQ | meanQ | ShadowFactor| if line.count("The 6 columns") > 0: is_data_started = True # Sanity check if not len(y) == len(dy): msg = "abs_reader: y and dy have different length" raise ValueError, msg # If the data length is zero, consider this as # though we were not able to read the file. if len(x) == 0: raise ValueError, "ascii_reader: could not load file" output.x = x[x != 0] output.y = y[x != 0] output.dy = dy[x != 0] output.dx = dx[x != 0] if data_conv_q is not None: output.xaxis("\\rm{Q}", output.x_unit) else: output.xaxis("\\rm{Q}", 'A^{-1}') if data_conv_i is not None: output.yaxis("\\rm{Intensity}", output.y_unit) else: output.yaxis("\\rm{Intensity}", "cm^{-1}") # Store loading process information output.meta_data['loader'] = self.type_name return output else: raise RuntimeError, "%s is not a file" % path return None