ans5_4.m

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% Interpolation using the four methods
x=[1 1.1 1.2 1.3 1.4];
y=[1.00000 1.23368 1.55271 1.99372 2.61170];
length_of_x=length(x);
scalar_x=x(1):0.05:x(length_of_x);
length_of_sx=length(scalar_x);
y_nearest = zeros(length(scalar_x),1);
y_linear = zeros(length(scalar_x),1);
y_spline = zeros(length(scalar_x),1);
y_cubic = zeros(length(scalar_x),1);
for i=1:length_of_sx
    y_nearest(i)=interp1(x,y,scalar_x(i),'nearest');
    y_linear(i) =interp1(x,y,scalar_x(i),'linear');
    y_spline(i) =interp1(x,y,scalar_x(i),'spline');
    y_cubic(i)  =interp1(x,y,scalar_x(i),'cubic');
end
subplot(2,2,1),plot(x,y,'*'),hold on,plot(scalar_x,y_nearest),title('method=nearest');
subplot(2,2,2),plot(x,y,'*'),hold on,plot(scalar_x,y_linear),title('method=linear');
subplot(2,2,3),plot(x,y,'*'),hold on,plot(scalar_x,y_spline),title('method=spline');
subplot(2,2,4),plot(x,y,'*'),hold on,plot(scalar_x,y_cubic),title('method=cubic');