Find second highest (max) in a range with asrol

[Youshida Koki]

I am using asrol (downloaded from the ssc). Is there a way to find second highest value or the second maximum in a rolling window.

[Attaullah Shah]

I have added max2, max3, max4, and max5 to the list of asrol statistics. These statistics will find the second, third, fourth, and the fifth largest values in a given range. As with other asrol's statistics, these new options will work in a rolling window or by groups.
The new statistics have the following rules:
1. Missing values are ignored
2. For stat(max2), the minimum number of non-missing observations are 2, otherwise the result will be missing.
3. The same rule is followed in other max functions, e.g. for max3, the minimum number of non-missing values are 3, and so on.

* Install the beta version from my site
net install asrol, from(http://fintechprofessor.com) replace

Examples:

*1. By groups
webuse grunfeld
bys company: asrol invest, stat(max2)

*2. Rolling window in groups
bys company: asrol invest, stat(max2) window(year 10)

list company year invest invest_max210 in 1/20
     +-------------------------------------+
     | company   year   invest   inves~210 |
     |-------------------------------------|
  1. |       1   1935    317.6           . |
  2. |       1   1936    391.8   317.60001 |
  3. |       1   1937    410.6   391.79999 |
  4. |       1   1938    257.7   410.60001 |
  5. |       1   1939    330.8   257.70001 |
     |-------------------------------------|
  6. |       1   1940    461.2   330.79999 |
  7. |       1   1941      512   461.20001 |
  8. |       1   1942      448         512 |
  9. |       1   1943    499.6         448 |
 10. |       1   1944    547.5   499.60001 |
     |-------------------------------------|
 11. |       1   1945    561.2       547.5 |
 12. |       1   1946    688.1   561.20001 |
 13. |       1   1947    568.9   688.09998 |
 14. |       1   1948    529.2   568.90002 |
 15. |       1   1949    555.1   529.20001 |
     |-------------------------------------|
 16. |       1   1950    642.9   555.09998 |
 17. |       1   1951    755.9   642.90002 |
 18. |       1   1952    891.2   755.90002 |
 19. |       1   1953   1304.4   891.20001 |
 20. |       1   1954   1486.7      1304.4 |
     +-------------------------------------+

Acknowledgement
The max2 function largely follows the code suggested by Nick Cox (reference).

[Youshida Koki]

Thanks. Works like a charm.