This article looks spot-on. Thanks for the link, Cris!! At 11:40 AM 9/23/2018, Cris Moore wrote:
least-squares fits on log-log plots often lead to the wrong exponent for power laws, since the data points out in the tail are noisier. one can also use a maximum-likelihood approach: see https://arxiv.org/abs/0706.1062 <https://arxiv.org/abs/0706.1062>
- Cris
On Sep 23, 2018, at 12:08 PM, Henry Baker <hbaker1@pipeline.com> wrote: At 08:24 AM 9/23/2018, Richard Howard wrote:
If the physics of the problem leads one to suspect a power law (or exponential), it is tempting to fit a straight line on a log-log (or log-linear) plot in Excel.
This does not weight all points (and their uncertainties) properly.
I can imagine that the error bounds on measurement errors don't scale properly after taking logs, but if the measurement errors are small compared with the underlying process variation (assuming that it is, indeed, a power law), then the weighting shouldn't be that far off.
Or is there some other issue that I'm missing here?