Dear Nick Cox
I believe I encounter a bug, or other wise unexpected behavior when trying to use the command -mipolate- with the option spline.
Code:
clear
input float(x F1)
        1 .11251517
        1 .11251517
1.0512711 .11455433
1.0512711 .11455433
1.0512711 .11455433
 1.105171         .
 1.105171         .
1.2214028         .
1.2214028         .
1.2214028         .
1.2840254 .12402454
 1.349859         .
1.6487212 .13951072
 1.733253 .14320229
 1.822119 .14712086
 1.822119 .14712086
 1.822119 .14712086
1.9155408 .15127993
1.9155408 .15127993
1.9155408 .15127993
1.9155408 .15127993
end
For example, if you take the data above, and try to interpolate it, It doesnt.
Code:
mipolate F1 x , gen(F2) spline
I dont see why such interpolation is not possible.
I also find that if i try to restrict the data using unique values of x, the mipolate does not interpolate where I think it should:
Code:
bysort x:gen n=_n
 mipolate F1 x if n==1, gen(F3) spline
sort x n
list x n F1 F2 F3, sep(0)


     +-------------------------------------------------+
     |        x   n         F1          F2          F3 |
     |-------------------------------------------------|
  1. |        1   1   .1125152   .11251517   .11251517 |
  2. |        1   2   .1125152   .11251517   .11251517 |
  3. | 1.051271   1   .1145543   .11455433   .11455433 |
  4. | 1.051271   2   .1145543   .11455433   .11455433 |
  5. | 1.051271   3   .1145543   .11455433   .11455433 |
  6. | 1.105171   1          .           .           . |
  7. | 1.105171   2          .           .    .1167151 |
  8. | 1.221403   1          .           .           . |
  9. | 1.221403   2          .           .   .12144209 |
 10. | 1.221403   3          .           .   .12144209 |
 11. | 1.284025   1   .1240245   .12402454   .12402454 |
 12. | 1.349859   1          .           .           . |
 13. | 1.648721   1   .1395107   .13951072   .13951072 |
 14. | 1.733253   1   .1432023   .14320229   .14320229 |
 15. | 1.822119   1   .1471209   .14712086   .14712086 |
 16. | 1.822119   2   .1471209   .14712086   .14712086 |
 17. | 1.822119   3   .1471209   .14712086   .14712086 |
 18. | 1.915541   1   .1512799   .15127993   .15127993 |
 19. | 1.915541   2   .1512799   .15127993   .15127993 |
 20. | 1.915541   3   .1512799   .15127993   .15127993 |
 21. | 1.915541   4   .1512799   .15127993   .15127993 |
     +-------------------------------------------------+
I wonder if there is something Im ignoring while doing this.
Thank you
Fernando