On Fri, 4 Jan 2019 18:54:47 +0100 Regina Henschel <rb.hensc...@t-online.de> wrote:
> Hi Dave, > > Dave Howorth schrieb am 02-Jan-19 um 18:12: > >[..] > > > > My spreadsheet data is in columns. Column A is the dates and column > > B is the times. Then ten columns of humidity data and eleven > > columns of temperature data. There are currently just over 5000 > > rows of samples. > > > > Making the chart was extremely slow. Every time I changed the Name > > of a line of the chart I had to wait whilst it cycled through > > several steps to make the change. Initially when I removed some > > empty columns from the data range, it took an age to do so. etc. > > Each data item produces an object, which is selectable in edit mode > of the chart. Your data produce 5000*(10+11)=105000 objects. That > cannot be fast. > > What is the purpose of the chart? You do not need 105000 objects to > illustrate something. > > With 5000 items in x-direction a lot of them will be on top of > others. My screen has only 1920 dots width and yours? Thanks, but this answers itself. If my screen or window has less pixels, then why create more objects and try to represent them? The chart software should be sampling the data appropriately to the resolution. And sure if I want to explore the detail, then I should be able to expand a section of the X-axis. I'm thinking of something like the graph module in emoncms, which handles this task with reasonable speed. > > Now I've created the chart and got some reasonable lines across it, > > but what I hope are the dates and times along the X axis are just a > > mess and I've no idea how to make them display usefully. > > I guess you have used a line chart. That x-axis cannot display time > units, the smallest unit is day. > A line chart shows an axis label for each data item. That is likely > not suitable for your chart. Correct, I'm using a line chart (i.e. the data I have are a number of time series). Thanks for the info about how it behaves. > You should try using an XY-chart. Thanks. Yes, that seems to work better. It's a lot faster as well :) > In case you need different positions inside one day, you should make > a separate column with added date and time values. Then use this > column for your x-axis. Yes, I'd created the column and will use it. > > The Y-axis is reasonable from 0 to 120, although it would be nice to > > trim the blank space at the top a bit, since the data can't exceed > > 100. > > > > I haven't found any way to select individual points on the chart to > > display the detailed value of that point or all the values at that > > time. > > Access to single points is only available in edit mode of the chart. > The information of the point is shown as tooltip. I don't see any tooltips? > You can display the value of data points as data label. Enable it in > edit mode in menu Insert > Data Label, or for a distinct point in its > context menu "Insert Single Data Label". > > In case you use an XY-chart you can generate a text column for labels > Such are called 'category' in the dialogs. But there is only one text > per row possible. > > Nor do I see a way to temporarily hide individual data lines to > > more clearly see other particular lines, for example. > > You can hide the associated column, then the line is removed from the > chart. When you show the column, the line is drawn again. OK, thanks. That works but is a bit laborious. > > If there's any way to do these things with an LO chart, and to > > speed it up, I'd be grateful for any pointers. Or if there are > > better options out there that can read .ods or .csv and display > > charts, that would also be interesting. > > It seems you want to explore your data. Some people have pointed to > the R-project. But I have never used it. Or you might find suitable > tools with search term 'data mining'. Thanks, I'll have a look. I might import the data into my emoncms system. > Kind regards > Regina -- To unsubscribe e-mail to: users+unsubscr...@global.libreoffice.org Problems? https://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: https://wiki.documentfoundation.org/Netiquette List archive: https://listarchives.libreoffice.org/global/users/ Privacy Policy: https://www.documentfoundation.org/privacy
