| T O P I C R E V I E W |
| cougar2 |
Posted - 01/06/2004 : 04:08:17 AM
Hi everyone,
I am plotting several 2d graphs each in one layer. The graphs need to match in x,y at their beginning and their end which they usually donīt because of certain difficulties in the measurement. Now, I can get around this by just scaling each layer differently so that I get the desired matching.
Question: Is there any way to do a calculation on the data plots so that I get the matching without scaling? This would come in handy because I think then I could automate this procedure. Just adding or multiplying by a constant doesnīt do because then I can only mathc the beginning and not the end (or vice versa). Also, I would like to make a 3d plot out of those different 2d graphs and in 3d I cannot scale each layer differently, so a calculation would be preferably.
I hope this problem isnīt too specific.
Cougar |
| 2 L A T E S T R E P L I E S (Newest First) |
| cougar2 |
Posted - 01/06/2004 : 07:45:45 AM
Hi Edgar,
thank you very much for your answer, it works very well.
Cougar |
| edgar.kaiser |
Posted - 01/06/2004 : 06:25:14 AM
Hi Cougar,
in a case like this you should consider to normalize your data. For example normalize your x data to an interval between z1 and z2:
Let x1i be the left end of your x-scale and x2i be the right end of the x-scale of dataset i. Perform the following transformations on all your n datasets:
Subtract x1i-z1 from all x values in dataset i. This transforms the left end to z1. x' = x - (x1i - z1)
To transform the right end to z2, do the following transformation to the resulting values x'. x'' = z1 + (x' - z1)*(z2 - z1)/(x2i - x1i)
Do the equivalent thing for the y-data.
For convenience normalizing is often performed with z1 = 0 ans z2 = 1. But this depends on your preferences.
Please note that the transformation will be different for the individual n datasets.
Hope this will help.
Regards,
Edgar
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