[email protected] wrote: > [-- text/plain, size 1.6K, charset utf-8, 42 lines, encoding quoted-printable > --] > > On Wed, Feb 04, 2026 at 09:44:08AM +0000, Chris Green wrote: > > Chris Green <[email protected]> wrote: > > > I'm looking for a program to do simple chart plotting, e.g. I have > > > some voltage measurements taken (say) once a minute and I want to > > > display how the voltage varies over (say) a day. So that's 1440 > > > measurements. > > > > > > This can be web or desktop, all I want is a window with a line drawn > > > across it really, a scale would be handy and the ability to show more > > > than one plot (e.g. voltage and current maybe). > > > > > > Source of data will almost certainly be a database as the data will be > > > coming from a headless Raspberry Pi and I already have that set up > > > writing values to a sqlite3 database. Obviously I can change the data > > > format, it is pretty simple to change it to CSV or whatever. > > > > > > Searching the main Debian repositories has brought up very little, > > > just a couple of libraries but no actual, runnable, programs. > > > > > > Can anyone suggest anything that will do what I want? > > > > > I was using the wrong "Look in" in my synaptic search, so I have found > > some possibilities now. > > The canonical answer is still gnuplot (although there are lots of > other solutions which are rather numerical/statistical packages with > very useful plotting capabilities, like R or NumPy). > > > However a program that will specifically allow 'compressing' the > > horizontal axis so that it can handle more points than will actually > > fit by averaging values would be ideal. So I'd still appreciate some > > ideas. > > For gnuplot, something like this? > > https://stackoverflow.com/questions/42855285/plotting-average-curve-for-points-in-gnuplot > No, not quite. It's not 'noisy' data that I'm trying to handle. If I just plotted 160 values I would get a reasonable looking line without having to do anything special to the data.
What I want to do is have a plot similar to the one above (without the vertical 'noise') but with lots more horizontal data items. E..g. at least 1440 and it would be nice to go even further to, say, 10080 points for a whole week plot at one minute intervals. -- Chris Green ·
