| Wind Speed Distribution Window | |
This window uses multiple algorithms to fit a Weibull distribution to wind speed data, and plots each of the resulting curves on the same graph along with the histogram of the measured speed data. To access this window, choose Analyze > Wind Speed Distribution from the menu.
For information about the algorithms, please see the article on Weibull fit algorithms.
In the top left corner of the window, you can choose a wind speed sensor from the drop-down box and specify the bin settings you want Windographer to use when plotting the frequency histogram of the measured data. Windographer automatically chooses reasonable bin settings, but you can change them if you wish. The bin settings do not affect any of the Weibull fit algorithms; they only affect the histogram of the measured data.
The filter controls provide several ways to filter the wind speed data that go into the frequency distribution. The article on filtering data gives details.
The table of results displays the following statistical parameters for each fitted distribution and for the actual measured data:
| Variable | Description |
|---|---|
| Weibull k | The shape factor of the two-parameter Weibull distribution. |
| Weibull A | The scale factor of the two-parameter Weibull distribution. |
| Mean | The simple mean value of the distribution. |
| Proportion Above Mean | The fraction of values in the distribution that exceed the mean value of the actual data. |
| Power Density | The mean wind power density of the distribution, assuming a constant air density of 1.225 kg/m3. |
| R Squared | The goodness-of-fit parameter that indicates how closely the fitted Weibull distribution matches the frequency histogram of the measured data. Values approaching one indicate a good fit. |
| Elapsed Time | The computational time that the algorithm required. |
See also