Graphs should start/end at the same position

> Do you think it would be better to modify the graphs so all of them
> start/end at the same time? (There is a small offset because the first
> and last fields aren't always the same)

I thought about this, but didn't bring it up yet, because it may not be
trivial to implement.


Idea #1: Does the graphing engine support defining the x axis limits
independent of displayed data points?  That is, can you draw a graph
like this (bad ASCII "art" ahead):

              +-----------------------------------+
              |                                   |
              |                       -O          |
    O--       | --O------O--        --            |
       --     |-            --    --              |
         --O--|               --O-                |
              |                                   |
              +-----------------------------------+
           x_start                              x_end

If so, I'd say try setting x_start to current system time minus whatever
period you're displaying and x_end to current system time.

By doing so, you'll discard a few data points left to x_start, and
you'll leave some graph space empty between the last O and x_end.  But
you'll have graphs displaying exactly the promised time period, and
graphs for that period will be easier to compare.  I'd say that's a fine
compromise.


Idea #2: If the graphing engine does not support redefining x axis
limits, you'll need to do some tricks: if there's no data point for
x_start, compute this point as the average of the two data points before
and after x_start; also add a "null" value for x_end.

(If you're cutting off values left to
x_start as discussed above, be sure to exclude them from the average.)