How to predict using interpolation or polyfit

Hi, I have data as below:

x y 1.2 2.3 4.8 2.7 5.8 3.5

and I want to predict for x is 2.7, what is y? Many thanks in advance,

[KSSV]

YOu have given only one value....provide both x and y....read about interp1

Answer 1

[Akira Agata]

...Or polyfit function, like:

xy = [1.2, 2.3;
  4.8, 2.7;
  5.8, 3.5];

p = polyfit(xy(:,1), xy(:,2), 2);
x = linspace(0,6);
y = polyval(p, x);

figure
plot(xy(:,1), xy(:,2),'ro');
hold on;
plot(x,y,'b:');
plot(2.7, polyval(p, 2.7), 'bo');
legend({'Data','polyfit','estimated value at x = 2.7'});