Sheehan Olver

`cheb2leg(::Matrix)` should do tensor product Cheb -> tensor product Leg

1

Note that `chebyshevtransform(::Matrix)` is a 2D transform: ```julia julia> using FastTransforms, ClassicalOrthogonalPolynomials julia> n,m = 3,4; f = (x,y) -> chebyshevt(n, x)chebyshevt(m,y) #13 (generic function with 1 method) julia> x...

Reorder `clenshaw` arguments

3

It's standard practice that `foo!(x, y, z)` modifies the first argument `x`.

Allow other than `Array` in libfasttransforms calls

1

I assume most of the calls work for strided arrays, correct? Or at least dense column major arrays?

Evaluation of SH/Zernike/Triangle expansions/polynomials?

15

@MikaelSlevinsky Is there a routine for pointwise evaluation for these bases? CC @tsgut

cheb2leg is slow

4

This seems very slow: ```julia julia> @time cheb2leg(randn(1_000)); 0.014712 seconds (9 allocations: 16.438 KiB) julia> @time cheb2leg(randn(10_000)); 0.491001 seconds (11 allocations: 156.969 KiB) julia> @time cheb2leg(randn(100_000)); 8.688441 seconds (11 allocations:...

How to transform from Legendre -> (1-x)^m * P_n^{2m,0}

2

I know they are hidden in the triangle transform, is there an easy way to call it?

Add examples folder showing full transform from points to coefficients

7

I'm always confused which points to use for which transform, especially with the SphericalHarmonic/TriangleHarmonics case. I think an examples folder would help here. If I figure out TriangleHarmonics, I'll add...

Have `paduapts` return the data as the transpose of the current format?

8

Right now `paduapts(n)` returns an N x 2 matrix. I'm proposing that it instead return a 2 x N matrix. The reason is that this allows for a no-op conversion...

Loosen limit n ≤ 4000 in gaussjacobi

3

This seems to be a hold over from MATLAB since ```julia julia> n=5000;a=rand(n);b=rand(n-1);@time eig(SymTridiagonal(a,b)); 4.166163 seconds (276.39 k allocations: 203.424 MB, 1.36% gc time) ````

Factor out exponential decay in weights

9

Suppose we want to find $$ \int_0^\infty f(x) exp(-x) dx $$ But we are not given $f(x)$, instead, we are given $g(x) exp(-x)$. Now we try Gauss--Laguerre as follows: ```julia...