add methods for median and quantile with function as the first argument. Fixes #141, fixes #27
#275
| Job | Run time |
|---|---|
| 1m 32s | |
| 1m 3s | |
| 1m 28s | |
| 2m 27s | |
| 2m 27s | |
| 1m 41s | |
| 3m 6s | |
| 1m 56s | |
| 2m 21s | |
| 2m 39s | |
| 2m 24s | |
| 1m 46s | |
| 3m 9s | |
| 27m 59s |