First version of PythonCharts.

The reason why it is so simple is that I wanted to get something into the project that people can use to compare different test runs easily. More functionality will come later.

tools/python_charts/src/gviz_api.py is a copy of the Google visualization Python API available from http://google-visualization-python.googlecode.com/svn/trunk/

Review URL: http://webrtc-codereview.appspot.com/257003

git-svn-id: http://webrtc.googlecode.com/svn/trunk@893 4adac7df-926f-26a2-2b94-8c16560cd09d

tools/python_charts/webrtc/data_helper.py

@@ -0,0 +1,134 @@
+#!/usr/bin/env python
+#  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+#
+#  Use of this source code is governed by a BSD-style license
+#  that can be found in the LICENSE file in the root of the source
+#  tree. An additional intellectual property rights grant can be found
+#  in the file PATENTS.  All contributing project authors may
+#  be found in the AUTHORS file in the root of the source tree.
+
+__author__ = 'kjellander@webrtc.org (Henrik Kjellander)'
+
+class DataHelper(object):
+  """
+  Helper class for managing table data.
+  This class does not verify the consistency of the data tables sent into it.
+  """
+
+  def __init__(self, data_list, table_description, names_list, messages):
+    """ Initializes the DataHelper with data.
+    
+    Args:
+      data_list: List of one or more data lists in the format that the 
+        Google Visualization Python API expects (list of dictionaries, one
+        per row of data). See the gviz_api.DataTable documentation for more 
+        info.
+      table_description: dictionary describing the data types of all
+        columns in the data lists, as defined in the gviz_api.DataTable
+        documentation.
+      names_list: List of strings of what we're going to name the data
+        columns after. Usually different runs of data collection. 
+      messages: List of strings we might append error messages to.
+    """
+    self.data_list = data_list
+    self.table_description = table_description
+    self.names_list = names_list
+    self.messages = messages
+    self.number_of_datasets = len(data_list)
+    self.number_of_frames = len(data_list[0])
+    
+  def CreateData(self, field_name, start_frame=0, end_frame=0):
+    """ Creates a data structure for a specified data field.
+    
+    Creates a data structure (data type description dictionary and a list 
+    of data dictionaries) to be used with the Google Visualization Python 
+    API. The frame_number column is always present and one column per data
+    set is added and its field name is suffixed by _N where N is the number 
+    of the data set (0, 1, 2...)
+    
+    Args:
+      field_name: String name of the field, must be present in the data
+        structure this DataHelper was created with.
+      start_frame: Frame number to start at (zero indexed). Default: 0.
+      end_frame: Frame number to be the last frame. If zero all frames 
+        will be included. Default: 0.
+        
+    Returns:
+      A tuple containing:
+      - a dictionary describing the columns in the data result_data_table below.
+        This description uses the name for each data set specified by 
+        names_list.  
+        
+        Example with two data sets named 'Foreman' and 'Crew':
+        {
+         'frame_number': ('number', 'Frame number'),
+         'ssim_0': ('number', 'Foreman'),
+         'ssim_1': ('number', 'Crew'),
+         }
+      - a list containing dictionaries (one per row) with the frame_number
+        column and one column of the specified field_name column per data 
+        set. 
+        
+        Example with two data sets named 'Foreman' and 'Crew':
+        [
+         {'frame_number': 0, 'ssim_0': 0.98, 'ssim_1': 0.77 },
+         {'frame_number': 1, 'ssim_0': 0.81, 'ssim_1': 0.53 },
+        ]
+    """
+    
+    # Build dictionary that describes the data types
+    result_table_description = {'frame_number': ('string', 'Frame number')} 
+    for dataset_index in range(self.number_of_datasets):
+      column_name = '%s_%s' % (field_name, dataset_index)
+      column_type = self.table_description[field_name][0]
+      column_description = self.names_list[dataset_index]
+      result_table_description[column_name] = (column_type, column_description)
+
+    # Build data table of all the data        
+    result_data_table = []
+    # We're going to have one dictionary per row. 
+    # Create that and copy frame_number values from the first data set
+    for source_row in self.data_list[0]:
+      row_dict = { 'frame_number': source_row['frame_number'] }
+      result_data_table.append(row_dict)
+    
+    # Pick target field data points from the all data tables
+    if end_frame == 0:  # Default to all frames
+      end_frame = self.number_of_frames
+      
+    for dataset_index in range(self.number_of_datasets):
+      for row_number in range(start_frame, end_frame):
+        column_name = '%s_%s' % (field_name, dataset_index)
+        # Stop if any of the data sets are missing the frame
+        try:
+          result_data_table[row_number][column_name] = \
+          self.data_list[dataset_index][row_number][field_name]
+        except IndexError:
+          self.messages.append("Couldn't find frame data for row %d "
+          "for %s" % (row_number, self.names_list[dataset_index])) 
+          break
+    return (result_table_description, result_data_table)
+
+  def GetOrdering(self, table_description):  
+    """ Creates a list of column names, ordered alphabetically except for the
+      frame_number column which always will be the first column.
+     
+      Args:
+        table_description: A dictionary of column definitions as defined by the
+          gviz_api.DataTable documentation.
+      Returns:
+        A list of column names, where frame_number is the first and the
+        remaining columns are sorted alphabetically.
+    """
+    # The JSON data representation generated from gviz_api.DataTable.ToJSon()
+    # must have frame_number as its first column in order for the chart to 
+    # use it as it's X-axis value series.
+    # gviz_api.DataTable orders the columns by name by default, which will 
+    # be incorrect if we have column names that are sorted before frame_number
+    # in our data table.
+    columns_ordering = ['frame_number']
+    # add all other columns:
+    for column in sorted(table_description.keys()):
+      if column != 'frame_number':
+        columns_ordering.append(column)
+    return columns_ordering