source: sasview/src/sas/sascalc/dataloader/readers/ascii_reader.py @ b36e7c7

magnetic_scatt
Last change on this file since b36e7c7 was 3bab401, checked in by krzywon, 6 years ago

Create a universal unit converter for all data loaders. refs #1111
  • Property mode set to 100644
File size: 6.5 KB
Line 
1"""
2    Generic multi-column ASCII data reader
3"""
4############################################################################
5# This software was developed by the University of Tennessee as part of the
6# Distributed Data Analysis of Neutron Scattering Experiments (DANSE)
7# project funded by the US National Science Foundation.
8# If you use DANSE applications to do scientific research that leads to
9# publication, we ask that you acknowledge the use of the software with the
10# following sentence:
11# This work benefited from DANSE software developed under NSF award DMR-0520547.
12# copyright 2008, University of Tennessee
13#############################################################################
14
15import logging
16from sas.sascalc.dataloader.file_reader_base_class import FileReader
17from sas.sascalc.dataloader.data_info import DataInfo, plottable_1D
18from sas.sascalc.dataloader.loader_exceptions import FileContentsException,\
19    DefaultReaderException
20
21logger = logging.getLogger(__name__)
22
23
24class Reader(FileReader):
25    """
26    Class to load ascii files (2, 3 or 4 columns).
27    """
28    # File type
29    type_name = "ASCII"
30    # Wildcards
31    type = ["ASCII files (*.txt)|*.txt",
32            "ASCII files (*.dat)|*.dat",
33            "ASCII files (*.abs)|*.abs",
34            "CSV files (*.csv)|*.csv"]
35    # List of allowed extensions
36    ext = ['.txt', '.dat', '.abs', '.csv']
37    # Flag to bypass extension check
38    allow_all = True
39    # data unless that is the only data
40    min_data_pts = 5
41
42    def get_file_contents(self):
43        """
44        Get the contents of the file
45        """
46
47        buff = self.readall()
48        filepath = self.f_open.name
49        lines = buff.splitlines()
50        self.output = []
51        self.current_datainfo = DataInfo()
52        self.current_datainfo.filename = filepath
53        self.reset_data_list(len(lines))
54
55        # The first good line of data will define whether
56        # we have 2-column or 3-column ascii
57        has_error_dx = None
58        has_error_dy = None
59
60        # Initialize counters for data lines and header lines.
61        is_data = False
62        # More than "5" lines of data is considered as actual
63        # To count # of current data candidate lines
64        candidate_lines = 0
65        # To count total # of previous data candidate lines
66        candidate_lines_previous = 0
67        # Current line number
68        line_no = 0
69        # minimum required number of columns of data
70        lentoks = 2
71        for line in lines:
72            toks = self.splitline(line.strip())
73            # To remember the number of columns in the current line of data
74            new_lentoks = len(toks)
75            try:
76                if new_lentoks == 0:
77                    # If the line is blank, skip and continue on
78                    # In case of breaks within data sets.
79                    continue
80                elif new_lentoks != lentoks and is_data:
81                    # If a footer is found, break the loop and save the data
82                    break
83                elif new_lentoks != lentoks and not is_data:
84                    # If header lines are numerical
85                    candidate_lines = 0
86                    self.reset_data_list(len(lines) - line_no)
87
88                self.current_dataset.x[candidate_lines] = float(toks[0])
89
90                if new_lentoks > 1:
91                    self.current_dataset.y[candidate_lines] = float(toks[1])
92
93                # If a 3rd row is present, consider it dy
94                if new_lentoks > 2:
95                    self.current_dataset.dy[candidate_lines] = \
96                        float(toks[2])
97                    has_error_dy = True
98
99                # If a 4th row is present, consider it dx
100                if new_lentoks > 3:
101                    self.current_dataset.dx[candidate_lines] = \
102                        float(toks[3])
103                    has_error_dx = True
104
105                candidate_lines += 1
106                # If 5 or more lines, this is considering the set data
107                if candidate_lines >= self.min_data_pts:
108                    is_data = True
109
110                if is_data and new_lentoks >= 8:
111                    msg = "This data looks like 2D ASCII data. Use the file "
112                    msg += "converter tool to convert it to NXcanSAS."
113                    raise FileContentsException(msg)
114
115                # To remember the # of columns on the current line
116                # for the next line of data
117                lentoks = new_lentoks
118                line_no += 1
119            except ValueError:
120                # ValueError is raised when non numeric strings conv. to float
121                # It is data and meet non - number, then stop reading
122                if is_data:
123                    break
124                # Delete the previously stored lines of data candidates if
125                # the list is not data
126                self.reset_data_list(len(lines) - line_no)
127                lentoks = 2
128                has_error_dx = None
129                has_error_dy = None
130                # Reset # of lines of data candidates
131                candidate_lines = 0
132
133        if not is_data:
134            self.set_all_to_none()
135            if self.extension in self.ext:
136                msg = "ASCII Reader error: Fewer than five Q data points found "
137                msg += "in {}.".format(filepath)
138                raise FileContentsException(msg)
139            else:
140                msg = "ASCII Reader could not load the file {}".format(filepath)
141                raise DefaultReaderException(msg)
142        # Sanity check
143        if has_error_dy and not len(self.current_dataset.y) == \
144                len(self.current_dataset.dy):
145            msg = "ASCII Reader error: Number of I and dI data points are"
146            msg += " different in {}.".format(filepath)
147            # TODO: Add error to self.current_datainfo.errors instead?
148            self.set_all_to_none()
149            raise FileContentsException(msg)
150        if has_error_dx and not len(self.current_dataset.x) == \
151                len(self.current_dataset.dx):
152            msg = "ASCII Reader error: Number of Q and dQ data points are"
153            msg += " different in {}.".format(filepath)
154            # TODO: Add error to self.current_datainfo.errors instead?
155            self.set_all_to_none()
156            raise FileContentsException(msg)
157
158        self.remove_empty_q_values()
159        self.current_dataset = self.set_default_1d_units(self.current_dataset)
160
161        # Store loading process information
162        self.current_datainfo.meta_data['loader'] = self.type_name
163        self.send_to_output()
Note: See TracBrowser for help on using the repository browser.