Line approximation from 5 points in Matlab

Hi, I would like to approximate a line in Matlab using 5 points with 5 x- and y-coordinates each.

I have two matrices as follows:

x = [365,672 526,974 593,972 660,972 819,974]

y = [249,996 250,001 250,005 250,007 250,0089]

I now would like to approximate a line that goes through these points. How do I accomplish that? I've tried Polyval and the "\-Operator", but that didn't quite work out. In the end, I need a function I could use later on.

Thanks!!

Answer 1

[Orion]

Hi,

interp1 is your friend

Answer 2

[Torsten]

x = [365.672 ; 526.974 ; 593.972 ; 660.972 ; 819.974];

y = [249.996 ; 250.001 ; 250.005 ; 250.007 ; 250.0089];

A =[1 x(1); 1 x(2); 1 x(3); 1 x(4); 1 x(5)];

b=y;

l=A\b;

The line then has the equation g(x)=l(1)+l(2)*x .

Best wishes

Torsten.

Answer 3

[Frank]

Perfect, both are working!