split fast transforms & plans in docs

Author: MikaelSlevinsky

docs/src/index.md

@@ -25,95 +25,99 @@ cheb2leg
 ```
 
 ```@docs
-plan_leg2cheb
+cjt
 ```
 
 ```@docs
-plan_cheb2leg
+icjt
 ```
 
 ```@docs
-cjt
+jjt
 ```
 
 ```@docs
-icjt
+nufft1
 ```
 
 ```@docs
-jjt
+nufft2
 ```
 
 ```@docs
-plan_cjt
+nufft3
 ```
 
 ```@docs
-plan_icjt
+inufft1
 ```
 
 ```@docs
-nufft1
+inufft2
 ```
 
 ```@docs
-nufft2
+paduatransform
 ```
 
 ```@docs
-nufft3
+ipaduatransform
 ```
 
 ```@docs
-inufft1
+sph2fourier
 ```
 
 ```@docs
-inufft2
+fourier2sph
 ```
 
+## Planning The Fast Transforms
+
+Most transforms have separate forward and inverse plans. In some instances, however, the inverse is in the sense of least-squares, and therefore only the forward transform is planned.
+
 ```@docs
-plan_nufft1
+plan_leg2cheb
 ```
 
 ```@docs
-plan_nufft2
+plan_cheb2leg
 ```
 
 ```@docs
-plan_nufft3
+plan_cjt
 ```
 
 ```@docs
-plan_inufft1
+plan_icjt
 ```
 
 ```@docs
-plan_inufft2
+plan_nufft1
 ```
 
 ```@docs
-paduatransform
+plan_nufft2
 ```
 
 ```@docs
-ipaduatransform
+plan_nufft3
 ```
 
 ```@docs
-plan_paduatransform!
+plan_inufft1
 ```
 
 ```@docs
-plan_ipaduatransform!
+plan_inufft2
 ```
 
 ```@docs
-sph2fourier
+plan_paduatransform!
 ```
 
 ```@docs
-fourier2sph
+plan_ipaduatransform!
 ```
 
 ```@docs

src/SphericalHarmonics/sphfunctions.jl

@@ -83,7 +83,11 @@ function maxcolnorm(A::AbstractMatrix)
 end
 
 doc"""
-Pointwise evaluation of spherical harmonic ``Y_{\ell}^m(\theta,\varphi)``.
+Pointwise evaluation of spherical harmonic:
+
+```math
+Y_\ell^m(\theta,\varphi) = \frac{e^{{\rm i} m\varphi}}{\sqrt{2\pi}} {\rm i}^{m+|m|}\sqrt{(\ell+\frac{1}{2})\frac{(\ell-m)!}{(\ell+m)!}} P_\ell^m(\cos\theta).
+```
 """
 sphevaluate(θ, φ, L, M) = sphevaluatepi(θ/π, φ/π, L, M)