lognormal_sd_from_mean_p90
lognormal_sd_from_mean_p90(mean, p90)Approximate SD on the original scale for a lognormal distribution.
Given the mean and 90th percentile, estimates a reasonable standard deviation of a lognormal variable on the original (un-logged) scale.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| mean | float | Arithmetic mean of the lognormal variable (on original scale). | required |
| p90 | float | 90th percentile (on original scale). | required |
Returns
| Name | Type | Description |
|---|---|---|
| float | Standard deviation (on the original scale). |