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nazg00l Newbie
Joined: 25 Jan 2006 Posts: 3

Posted: Wed Jan 25, 2006 11:36 am Post subject: plotting several overlapping data ranges on an XY plot 


Is there any way to plot several data series on a common XY chart? Individual series cover the same X range, but the actual sampling points are different so there is no way to bring them to a "common X" format.
Simply specifying the ranges separated with semicolons produces a chart that looks OK, but all the series are treated as the same data range and therefore cannot be formatted individually. Not to mention that the end of one series gets connected with a line to the start of the second series and so on. How can this be done? It is a trivial function in plotting software like Origin or Grapher, but I can't seem to find an "Add Data Series to Chart" function in Calc... I have searched the Net, but can't find anything useful.
Any help will be greatly appreciated!
Andrzej Sawula 

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jrkrideau Super User
Joined: 08 Aug 2005 Posts: 6732 Location: Kingston ON Canada

Posted: Wed Jan 25, 2006 12:48 pm Post subject: Re: plotting several overlapping data ranges on an XY plot 


nazg00l wrote:  Is there any way to plot several data series on a common XY chart? Individual series cover the same X range, but the actual sampling points are different so there is no way to bring them to a "common X" format. 
You've lost me here. Are you saying that the X axis is too large or that the Yaxis is too large?
Quote:  Simply specifying the ranges separated with semicolons produces a chart that looks OK, but all the series are treated as the same data range and therefore cannot be formatted individually. Not to mention that the end of one series gets connected with a line to the start of the second series and so on. How can this be done? It is a trivial function in plotting software like Origin or Grapher, but I can't seem to find an "Add Data Series to Chart" function in Calc... I have searched the Net, but can't find anything useful.
Any help will be greatly appreciated!
Andrzej Sawula 
I think I am missing something here but why not just put the different ranges of the y variable in separate columns and graph them? You maintain a common xaxis and have separate descrete lines for each yvariable. _________________ jrkrideau
Kingston ON Canada
Currently using Windows 7 & OOo 3.4.0 and Ubuntu 12.04 & LibreOffice 3.5.2.2 

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nazg00l Newbie
Joined: 25 Jan 2006 Posts: 3

Posted: Wed Jan 25, 2006 1:19 pm Post subject: 


OK, so an example would go like that:
Two series of data, both covering the 010 X range.
Series 1:
Code:  X: 1 3 4 6 7 9 10
Y: something 
Series 2:
Code:  X: 1 2 3 5 6 8 10
Y: something 
So both series cover the same range, but the actual X points (sampling points) are different. X is real, not integer, of course... So building a common X column is impossible. 

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David Super User
Joined: 24 Oct 2003 Posts: 5668 Location: Canada

Posted: Wed Jan 25, 2006 2:31 pm Post subject: 


This is a digital machine, so you can't get continuous "real" values". In that case, determine at first your required accuracy [and it is a graph, so you won't see minute differences over a large amount of data.] With that in mind, suppose you set up a list of values down column A, such as 0, 0.1, 0.2, 0.3, .... Yes, you'll have a hundred, but there's lots of room and assitance with that by dragging a series. Then you can have one set of relational results in column B and another in column C. Choose all to draw the graph, then change axis values later [steps of 1?]
Personally, I'd use available math programs for this sort of thing, not a spreadsheet. I've mentioned a couple in the recent and distant past
David. 

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jrkrideau Super User
Joined: 08 Aug 2005 Posts: 6732 Location: Kingston ON Canada

Posted: Thu Jan 26, 2006 6:19 am Post subject: 


nazg00l wrote:  OK, so an example would go like that:
Two series of data, both covering the 010 X range.
Series 1:
Code:  X: 1 3 4 6 7 9 10
Y: something 
Series 2:
Code:  X: 1 2 3 5 6 8 10
Y: something 
So both series cover the same range, but the actual X points (sampling points) are different. X is real, not integer, of course... So building a common X column is impossible. 
Why? I must be really missing something here. If x is real I don't see that it matters. You have a xaxis range from 110 and values for Y1 and Y1 so that all (x,y) points are within the 110 range. Presumabley both x and y are continuous variables. That's all you need.
It is only when the xaxis is categorical that you need to have the same xvalues, that is, for something like a line chart or a bar chart. The choice of the numbers on the x and y axes for an XY graph are purely arbitrary ( well as long as we include the 110 range ) _________________ jrkrideau
Kingston ON Canada
Currently using Windows 7 & OOo 3.4.0 and Ubuntu 12.04 & LibreOffice 3.5.2.2 

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nazg00l Newbie
Joined: 25 Jan 2006 Posts: 3

Posted: Fri Jan 27, 2006 2:42 am Post subject: 


Yes, that should not matter  but it does. When processing a 2nd series of data, Calc expects the Y data to correspond to the 1st column X values, not to their own specified ones...
EDIT: I found a way to do this. Somewhat counterintuitive and limited, but still... The solution is to insert X data in the 1st column and then individual series of Y data in individual columns, like that:
Code:  series 1 X  series 1 Y 
series 1 X  series 1 Y 
series 1 X  series 1 Y 
...  ... 
series 1 X  series 1 X 
series 1 X  series 1 X 
series 2 X   series 2 Y
series 2 X   series 2 Y
series 2 X   series 2 Y
...   ...
series 2 X   series 2 Y 
The problem with such a "solution" is that the maximum number of rows is 65535, which limits the size of data if one wants to plot e.g. 10 series on the same chart... But it should work for me still.
Thanks everybody for your input! 

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jrkrideau Super User
Joined: 08 Aug 2005 Posts: 6732 Location: Kingston ON Canada

Posted: Fri Jan 27, 2006 5:46 am Post subject: 


nazg00l wrote:  Yes, that should not matter  but it does. When processing a 2nd series of data, Calc expects the Y data to correspond to the 1st column X values, not to their own specified ones...
EDIT: I found a way to do this. Somewhat counterintuitive and limited, but still... The solution is to insert X data in the 1st column and then individual series of Y data in individual columns, like that:
Code:  series 1 X  series 1 Y 
series 1 X  series 1 Y 
series 1 X  series 1 Y 
...  ... 
series 1 X  series 1 X 
series 1 X  series 1 X 
series 2 X   series 2 Y
series 2 X   series 2 Y
series 2 X   series 2 Y
...   ...
series 2 X   series 2 Y 
The problem with such a "solution" is that the maximum number of rows is 65535, which limits the size of data if one wants to plot e.g. 10 series on the same chart... But it should work for me still.
Thanks everybody for your input! 
Yes. That is what I tried to explain and didn't make clear. Sorry. . I could see it in my mind.!
I think that David's suggestion of a dedicated math or graphics package is probably the best way to go. He has suggested two here http://www.oooforum.org/forum/viewtopic.phtml?p=121890&highlight=#121890 and I would add R http://www.rproject.org/ and gnuplot http://t16web.lanl.gov/Kawano/gnuplot/indexe.html
Spreadsheets are good for many things but specialised programs have there place when you need specific tools. And spreadsheets just don't have the graphics capacity for good scientific output in many cases. _________________ jrkrideau
Kingston ON Canada
Currently using Windows 7 & OOo 3.4.0 and Ubuntu 12.04 & LibreOffice 3.5.2.2 

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