\documentclass[border=10pt]{standalone}\usepackage{textgreek}\usepackage[inline]{asymptote}\usepackage{lmodern}\begin{document}\begin{asy}size(200);import graph;pair[] botP={(0,0.09),(0.252,0.196),(0.383,0.429),(0.479,0.588),(0.574,0.668),(0.733,0.726),(0.883,0.747),(1,0.747),};pair[] topP={(0,0.341),(0.252,0.451),(0.383,0.677),(0.479,0.841),(0.574,0.92),(0.733,0.977),(0.883,0.993),(1,1),};pair[] midP=0.5*(topP+botP);guide gtop=graph(topP,operator..);guide gbot=graph(botP,operator..);guide gmid=graph(midP,operator..);real f(real x){real t=times(gmid,x)[0];return point(gmid,t).y;};real s(real x){real tt=times(gtop,x)[0];real tb=times(gbot,x)[0];return point(gtop,tt).y-point(gbot,tb).y;};real xmin=0, xmax=1;pen[] clrs={rgb(0.988,0.847,0.796),rgb(0.969,0.592,0.502),rgb(0.953,0.365,0.29),rgb(0.933,0.188,0.165),rgb(0.933,0.114,0.137),};
Source: TeX.SE