import graph;

size(140mm,70mm,IgnoreAspect);
scale(false);
real[] x={1,3,4,5,6};
real[] y={1,5,2,0,4};

marker mark=marker(scale(1mm)*cross(6,false,r=0.35),red,Fill);

draw(graph(x,y,Hermite),"Hermite Spline",mark);
xaxis("$x$",Bottom,LeftTicks(x));
yaxis("$y$",Left,LeftTicks);
attach(legend(),point(NW),40S+30E,UnFill);