问在Matlab中绘制多边形

EN

function x = plotpint (coef, x1, x2,numpoints) 

%coef: polynom's coefficient array x1,x2 : intervals
%numpoints: the number of data points to be plotted

a=linspace(x1,x2,numpoints); % linspace of intervals and numpoints
b=polyval(coef,a); %values of given coef polynom for intervals
c=polyint(coef); % coef array of given coef's integral of polynom ( don't care here)
d=polyval(c,a); % values of c's polynom(integral of polynom) ( don't care here)
plot(a,b); % plotting polynom and integral of polynom
title('rer'); 

end