Kaiser-Bessel window as wolframscript rational 4-term cosine sum {402 498 99 1}/1000
KaiserBesselWindow[x]
Plot[KaiserBesselWindow[x], {x, -1, 1}]
→ -Graphics-Plot3D[KaiserBesselWindow[x]KaiserBesselWindow[y], {x, -1, 1}, {y, -1, 1}, PlotRange -> All, Exclusions -> None]
→ -Graphics3D-KaiserBesselWindow[0.1]
→ 0.8351741286474688