cdof=[0 2/3 4/3 2 8/3 10/3 4 5 6 7];
vdof=sin(cdof);
conecg=[1 2;2 3;3 4];
coordg=[0 2 4 7];
conecdof=[1 2 3 4;4 5 6 7;7 8 9 10];
pp=3;
xh=-1:0.05:1;#drawing points
nhat=size(xh,2);
nel=size(conecg,1);npe=size(conecg,2);
nodg=size(coordg,2);
[g dg d2g] = masterp1(1,xh);
[sf dsf ddsf]=masterlag(pp,xh);
for k=1:nel
XX(:,1)=coordg(:,conecg(k,1));
XX(:,2)=coordg(:,conecg(k,2));
x=zeros(1,nhat); dx=zeros(1,nhat);
for i=1:npe
 x(1,:)=x(1,:)+XX(1,i)*g(i,:);
 dx(1,:)=dx(1,:)+XX(1,i)*dg(i,:);
end
f=vdof(conecdof(k,:))*sf;
df=vdof(conecdof(k,:))*dsf./dx;
plot(x,sin(x),"or","linewidth",1); hold on;
plot(x,f,"r","linewidth",2); hold on;
plot(x,cos(x),"ob","linewidth",1); hold on;
plot(x,df,"b","linewidth",2); hold on;
hold on;
end
hold off