Scilab5_1

clc
vX = [-0.3 0.1 0.5 0.9 1.3 1.7 2.1];
vY = [-1.3 2.2 3.5 5.8 7.2 6.0 5.8];
X=1.43;
vTemp=[0 0 0 0 0 0 0]
j=1;
i=1;
n=7;
Px=0;
xi=vX(1);
xii=vX(1);
x0=vX(1);
y0=vX(1);
Ptmp=1;

for i = 1:n;
yi=vY(i);
xii=vX(i);

for j = 1:n;
xi=vX(j);
if (xii<>xi) then
Ptmp=Ptmp*((X-xi)/(xii-xi));
end
end

Px=Px+Ptmp*yi
vTemp(i)=Px;
Ptmp=1;
end
Px
vTemp

plot2d(vX, vTemp, style=[color("magenta")], leg="Лагранж");
d=splin(vX,vTemp);
S=interp(-0.3:0.01:2.1, vX,vTemp,d);
plot2d(vX',vTemp',-1);
plot2d((-0.3:0.01:2.1)',S',9,'000')