clear?all?
clc
hold?off
%sample?of?size?N
N=100;

%sample?generation
x1=rand（N1）-0.5;
x2=rand（N1）-0.5;
x3=rand（N1）-0.5;

plot（x1x2‘o‘）
hold?on
plot（x1x3‘o‘）

%model?evaluations
y=4*x1.^2+3*x2+x3;

%set?n.?of?stripes
r=10;

for?i=1:r
t=（i-1）/r-0.5;
ind=find（x1t）;
condmean1（i）=mean（y（ind））;
ind=find（x2t）;
condmean2（i）=mean（y（ind））;
ind=find（x3