data point not distributed equally on charts with date on the X-axis

users
#1

Hello list,

I'm trying to visualize a few CSVs from my router. The original CSV
contains the date in epoch plus a few zeroes. I have converted that to
date using =(A2/1000)/86400+25569.

From that, I tried to generate a chart and the values pooled at certain
points on the X-Axis, instead of distributing evenly. See an example here:

https://owncloud.7183.org/index.php/s/qf42u9QpP9YooHY

There are two charts in the document, the first labeled using the first
column, the second labeled using the second column. Both should look
equal, but obviously don't. Any idea why this happens and how to fix this?

Thanks!

Harald

#2

Hi,

Hello list,

I'm trying to visualize a few CSVs from my router. The original CSV
contains the date in epoch plus a few zeroes. I have converted that to
date using =(A2/1000)/86400+25569.

From that, I tried to generate a chart and the values pooled at certain
points on the X-Axis, instead of distributing evenly. See an example here:

https://owncloud.7183.org/index.php/s/qf42u9QpP9YooHY

There are two charts in the document, the first labeled using the first
column, the second labeled using the second column. Both should look
equal, but obviously don't. Any idea why this happens and how to fix this?

Obviously, Calc uses the date instead of date+hour to define the
category. Why, I do not know. But it's clear that in this case you do
not have true categories because you have only one value for each
category. In such cases you should use XY chart type instead of line,
because what you want to show is a function F(t).

If you really want use line chart + categories, it works if you replace
the formula in column B by:
=TEXT((A2/1000)/86400+25569;"JJ/MM/AAAA HH:MM:SS")

Another point: you should use a secondary Y-axis to make state changes
visible.

Best regards.
JBF

#3

Thank you, that was the solution!