Apache OpenOffice (AOO) Bugzilla – Issue 40172
Y overflow in YX-Charts (data clipping error)
Last modified: 2013-02-24 21:21:56 UTC
When I display a XY- chart and rescale Y manually to a value very much slower than the default, strange Lines may appear, which look like an overflow. In the sample there are 3 curves which differ strongly in their value range. Therefore I created 3 equivalent charts with different Y scaling. The Chart with the lowest Y range shows strange lines, which look like an overflow of something.
Created attachment 21225 [details] The buggy diagram (note: green and blue curve should be invisible due to their big values)
Created attachment 21226 [details] This is the spreadsheet, which shows that behaviour on my machine
The problem here is that for clipping the data points are transformed to graphic coordinates, which are integer values. The 10^6 values become larger that some billions in screen coordinates as the scale spans only about 10^-2. As a results the integers overflow (a 3*10^8 becomes sth like -10^8) and the clipping returns the vertical lines. As a solution the clipping has to be done in the value coordinate system using double values. This is too much effort for the old chart. In the new chart it might already been fixed, but at least we will address it there. As a workaround, you can build a new chart with only the interesting series selected. The only difference (apart from the buggy lines) will be the that in the legend you will only see an entry for one series and not for the other two, but as you can't see the series themselves this should be no big deal.
-> BM: Thx for the superb description and the workaround. -> kunkunuzzu: I think its possible to work with the workaround. I case of the efford -> Target office later -> Iha: pls take care of that Issue for the new Chart.
I will check this.
This bug has vanished in the chart reimplementation in CWS chart2mst3.
changed prio
Fixed in CWS chart2mst3. re-open issue and reassign to kla@openoffice.org
reassign to kla@openoffice.org
reset resolution to FIXED
Changed target to 2.x
changed target to 2.3
seen ok -> verified
Fixed in 680 m215, closing.