Drawing daily Min/Max graph from a source with UN values
I'm fetching data from my radio weather station and put them into
graphs. A graph that shows the temperature over the day, and follow up
graphs that show min, max and average temps from the previous days.
Unfortunately some times the transmission from the weather station
fails, and I have unknown values for a few minutes. A short gap in the
daily temps gauge is not a problem, but for any day with a UN Value I do
not get min/max/average calculations...
That is the command for calculation the weekly values: