sample_median - bruno-beloff/scs_analysis GitHub Wiki

docs > software repositories > scs_analysis > commands > filtering and aggregating data


DESCRIPTION

The sample_median utility provides a median filter - the filter maintains an odd-numbered window on the input data sequence, and outputs the middle item in the sorted list of items. The user can specify the size of the window.

Input data is typically in the form of a JSON document. A command parameter specifies the path to the node within the document that is to be filtered. The node is typically a leaf node integer or float. The output of the sample_median utility includes the source value, and the smoothed value.

SYNOPSIS

sample_median.py [-w SIZE] [-p PRECISION] [-v] [PATH]

Options
--version show program's version number and exit
-h, --help show this help message and exit
--w WINDOW, --window=WINDOW window size (must be an odd number, default 3)
--p PRECISION, --prec=PRECISION precision (default 0 decimal places)
-v, --verbose report narrative to stderr

EXAMPLES

aws_topic_history.py -m60 /orgs/south-coast-science-demo/brighton/loc/1/gases | ./sample_median.py -w 3 -p 1 val.CO.cnc

DOCUMENT EXAMPLE - INPUT

{"tag": "scs-bgx-401", "rec": "2018-03-27T09:54:41.042+00:00", "val": {"NO2": {"weV": 0.29563, "aeV": 0.280879, "weC": 0.009569, "cnc": 61.0}, "Ox": {"weV": 0.406819, "aeV": 0.387443, "weC": -0.010706, "cnc": 34.7}, "NO": {"weV": 0.319692, "aeV": 0.292129, "weC": 0.028952, "cnc": 165.5}, "CO": {"weV": 0.395819, "aeV": 0.289317, "weC": 0.113108, "cnc": 311.3}, "sht": {"hmd": 82.4, "tmp": 12.6}}}

DOCUMENT EXAMPLE - OUTPUT

{"rec": "2018-03-27T12:11:21.028+00:00", "val": {"CO": {"cnc": {"src": 262.1, "med": 368.0}}}}

RESOURCES

https://en.wikipedia.org/wiki/Median_filter