Filter

To accommodate Mermaid testing values in the .vit file, we need to filter out certain times. This is easily done by using a .yml file. .yml files ar easy to read and easy to modify.

The standard setup of the time_filter is the following:

# Mermaid number
1:
  # Time filter:
  # structure of the time filter is a list of lists with UTCDateTime stamps.
  #  [ [starttime , endtime],
  #    [starttime , endtime],
  #     ...                   ]
  # The location within the time window will not be considered when reading
  # the mermaid data.
  time_filter: [["2000-01-01T00:00:01" , "2018-12-27T01:37:34"]]
2:
  time_filter: [["2000-01-01T00:00:01", "2018-12-28T16:55:32"]]
3:
  time_filter: [["2000-01-01T00:00:01", "2019-01-01T21:13:03"],
                ["2019-01-02T00:44:03", "2030-01-02T00:14:03"]]
...

For each Mermaid there is a time_filter, and each time_filter, there can be a list of values, such that multiple windows can be filtered out. The filter is loaded as a part of the file loading process. I decided for this type of setup, because it is very simple to possible add other filters in the future that can also be specified in the same .yml file.

The filter is called by merplot.mermaid_plot.MermaidLocations .from_vit_file() and the filter is used to exclude certain dates in the mermaid tracks.