source: sasview/DataLoader/readers/danse_reader.py @ 2e9b98c

"""
    DANSE/SANS file 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. 

If you use DANSE applications to do scientific research that leads to 
publication, we ask that you acknowledge the use of the software with the 
following sentence:

"This work benefited from DANSE software developed under NSF award DMR-0520547." 

copyright 2008, University of Tennessee
"""

import math
import os
import copy
import numpy
import logging
from DataLoader.data_info import Data2D, Detector

# Look for unit converter
has_converter = True
try:
    from data_util.nxsunit import Converter
except:
    has_converter = False

class Reader:
    """
        Example data manipulation
    """
    ## File type
    type = ["DANSE files (*.sans)|*.sans"]
    ## Extension
    ext  = ['.sans', '.SANS']    
        
    def read(self, filename=None):
        """
            Open and read the data in a file
            @param file: path of the file
        """
        
        read_it = False
        for item in self.ext:
            if filename.lower().find(item)>=0:
                read_it = True
                
        if read_it:
            try:
                 datafile = open(filename, 'r')
            except :
                raise  RuntimeError,"danse_reader cannot open %s"%(filename)
            
            
            # defaults
            # wavelength in Angstrom
            wavelength = 10.0
            # Distance in meter
            distance   = 11.0
            # Pixel number of center in x
            center_x   = 65
            # Pixel number of center in y
            center_y   = 65
            # Pixel size [mm]
            pixel      = 5.0
            # Size in x, in pixels
            size_x     = 128
            # Size in y, in pixels
            size_y     = 128
            # Format version
            fversion   = 1.0
            
            output = Data2D()
            output.filename = os.path.basename(filename)
            detector = Detector()
            output.detector.append(detector)
            
            output.data = numpy.zeros([size_x,size_y])
            output.err_data = numpy.zeros([size_x,size_y])
            
            data_conv_q = None
            data_conv_i = None
            
            if has_converter == True and output.Q_unit != 'A^{-1}':
                data_conv_q = Converter('A^{-1}')
                # Test it
                data_conv_q(1.0, output.Q_unit)
                
            if has_converter == True and output.I_unit != 'cm^{-1}':
                data_conv_i = Converter('cm^{-1}')
                # Test it
                data_conv_i(1.0, output.I_unit)            
        
            read_on = True
            while read_on:
                line = datafile.readline()
                if line.find("DATA:")>=0:
                    read_on = False
                    break
                toks = line.split(':')
                if toks[0]=="FORMATVERSION":
                    fversion = float(toks[1])
                if toks[0]=="WAVELENGTH":    
                    wavelength = float(toks[1])                
                elif toks[0]=="DISTANCE":
                    distance = float(toks[1])
                elif toks[0]=="CENTER_X":
                    center_x = float(toks[1])
                elif toks[0]=="CENTER_Y":
                    center_y = float(toks[1])
                elif toks[0]=="PIXELSIZE":
                    pixel = float(toks[1])
                elif toks[0]=="SIZE_X":
                    size_x = int(toks[1])
                elif toks[0]=="SIZE_Y":
                    size_y = int(toks[1])
            
            # Read the data
            data = []
            error = []
            if fversion==1.0:
                data_str = datafile.readline()
                data = data_str.split(' ')
            else:
                read_on = True
                while read_on:
                    data_str = datafile.readline()
                    if len(data_str)==0:
                        read_on = False
                    else:
                        toks = data_str.split()
                        try:
                            val = float(toks[0])
                            err = float(toks[1])
                            if data_conv_i is not None:
                                val = data_conv_i(val, units=output.y_unit)
                                err = data_conv_i(err, units=output.y_unit)
                            data.append(val)
                            error.append(err)
                        except:
                            logging.info("Skipping line:%s,%s" %( data_str,sys.exc_value))
            
            # Initialize 
            x_vals = []
            y_vals = [] 
            ymin = None
            ymax = None
            xmin = None
            xmax = None
            
            # Qx and Qy vectors
            theta = pixel / distance / 100.0
            stepq = 4.0*math.pi/wavelength * math.sin(theta/2.0) 
            for i_x in range(size_x):
                theta = (i_x-center_x+1)*pixel / distance / 100.0
                qx = 4.0*math.pi/wavelength * math.sin(theta/2.0)
                
                if has_converter == True and output.Q_unit != 'A^{-1}':
                    qx = data_conv_q(qx, units=output.Q_unit)
                
                x_vals.append(qx)
                if xmin==None or qx<=xmin:
                    xmin = qx
                if xmax==None or qx>=xmax:
                    xmax = qx
            
            ymin = None
            ymax = None
            for i_y in range(size_y):
                theta = (i_y-center_y+1)*pixel / distance / 100.0
                qy = 4.0*math.pi/wavelength * math.sin(theta/2.0)
                
                if has_converter == True and output.Q_unit != 'A^{-1}':
                    qy = data_conv_q(qy, units=output.Q_unit)
                
                y_vals.append(qy)
                if ymin==None or qy<ymin:
                    ymin = qy
                if ymax==None or qy>ymax:
                    ymax = qy
            
            # Store the data in the 2D array
            itot = 0
            i_x  = 0
            i_y  = -1
            
            for i_pt in range(len(data)):
                try:
                    value = float(data[i_pt])
                except:
                    # For version 1.0, the data were still
                    # stored as strings at this point.
                    logging.info("Skipping entry (v1.0):%s,%s" %(str(data[i_pt]), sys.exc_value))
                
                # Get bin number
                if math.fmod(i_pt, size_x)==0:
                    i_x = 0
                    i_y += 1
                else:
                    i_x += 1
                    
                output.data[i_y][i_x] = value       
                #output.data[size_y-1-i_y][i_x] = value
                if fversion>1.0:
                    output.err_data[i_y][i_x] = error[i_pt]
                    #output.err_data[size_y-1-i_y][i_x] = error[i_pt]
                
                
            # Store all data ######################################
            # Store wavelength
            if has_converter==True and output.source.wavelength_unit != 'A':
                conv = Converter('A')
                wavelength = conv(wavelength, units=output.source.wavelength_unit)
            output.source.wavelength = wavelength
                
            # Store distance
            if has_converter==True and detector.distance_unit != 'm':
                conv = Converter('m')
                distance = conv(distance, units=detector.distance_unit)
            detector.distance = distance
            
            # Store pixel size
            if has_converter==True and detector.pixel_size_unit != 'mm':
                conv = Converter('mm')
                pixel = conv(pixel, units=detector.pixel_size_unit)
            detector.pixel_size.x = pixel
            detector.pixel_size.y = pixel

            # Store beam center in distance units
            detector.beam_center.x = center_x*pixel
            detector.beam_center.y = center_y*pixel
            
            # Store limits of the image (2D array)
            xmin    =xmin-stepq/2.0
            xmax    =xmax+stepq/2.0
            ymin    =ymin-stepq/2.0
            ymax    =ymax+stepq/2.0
            
            if has_converter == True and output.Q_unit != 'A^{-1}':
                xmin = data_conv_q(xmin, units=output.Q_unit)
                xmax = data_conv_q(xmax, units=output.Q_unit)
                ymin = data_conv_q(ymin, units=output.Q_unit)
                ymax = data_conv_q(ymax, units=output.Q_unit)
            output.xmin = xmin
            output.xmax = xmax
            output.ymin = ymin
            output.ymax = ymax
            
            # Store x and y axis bin centers
            output.x_bins     = x_vals
            output.y_bins     = y_vals
           
            # Units
            if data_conv_q is not None:
                output.xaxis("\\rm{Q_{x}}", output.Q_unit)
                output.yaxis("\\rm{Q_{y}}", output.Q_unit)
            else:
                output.xaxis("\\rm{Q_{x}}", 'A^{-1}')
                output.yaxis("\\rm{Q_{y}}", 'A^{-1}')
                
            if data_conv_i is not None:
                output.zaxis("\\{I(Q)}", output.I_unit)
            else:
                output.zaxis("\\rm{I(Q)}","cm^{-1}")
           
            if not fversion>=1.0:
                raise ValueError,"Danse_reader can't read this file %s"%filename
            else:
                logging.info("Danse_reader Reading %s \n"%filename)
                return output
        
        return None

if __name__ == "__main__": 
    reader = Reader()
    print reader.read("../test/MP_New.sans")