|
 Correlation |
| Posted by Fredrik on Sep-10-2018 22:01 |
|
Hi,
How is the correlation coefficient obtained from the trendLayer computed? Is it the Pearson correlation?
Best,
Fredrik |
| Re: Correlation |
| Posted by Peter Kwan on Sep-11-2018 18:44 |
|
Hi Fredrik,
For linear regression with linear axes, it is the Pearson correlation. For log axis, the data may need to be adjusted before computation the correlation.
For example, a chart with a log scale y-axis and linear scale x-axis may look like a perfect straight line, even if the data values are not directly proportional to each other (which means if would not be a straight line if linear axes are used). Most people expect data points that lies exactly on a straight line to be perfectly correlated. So for a chart with non-linear scale, the correlation computation are adjusted for it to be consistent with the line that is actually plotted. (You may image that the correlation is done on the graphical coordinates of the points, which may not have a linear relationship with the original data.)
Regards
Peter Kwan |
|
Forum Home
Search
Message List
Post Message