- Global SH_Xrotate90  (shtns_cfg shtns, cplx *Qlm, cplx *Rlm)
- Rotate SH representation around X axis by 90 degrees.  
- Global SH_Yrotate  (shtns_cfg shtns, cplx *Qlm, double alpha, cplx *Rlm)
- Rotate SH representation around Y axis by alpha (in radians).  
- Global SH_Yrotate90  (shtns_cfg shtns, cplx *Qlm, cplx *Rlm)
- Rotate SH representation around Y axis by 90 degrees.