IRC-SPHERE/HyperStream

# The MIT License (MIT) # Copyright (c) 2014-2017 University of Bristol
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
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#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
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#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
#  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
#  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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from hyperstream.stream import StreamInstance
from hyperstream.tool import Tool, check_input_stream_count


class ListDictMean(Tool):
    """
    Take the component-wise mean of dicts in the list
    """
    def __init__(self):
        super(ListDictMean, self).__init__()

    @check_input_stream_count(1)
    def _execute(self, sources, alignment_stream, interval):
        for time, data in sources[0].window(interval, force_calculation=True):
            dict_mean = dict()
            if len(data)==0:
                yield StreamInstance(time, dict_mean)
            inv_len_data = 1/float(len(data))
            for item in data:
                for key in item.keys():
                    try:
                        dict_mean[key] = dict_mean[key] + item[key]*inv_len_data
                    except KeyError:
                        dict_mean[key] = item[key]*inv_len_data
            yield StreamInstance(time, dict_mean)