Could someone explain this straight line function?

I found this bit of code in another help thread:

func = @(x)a(1) + (a(2)-b(2))/(a(1)-b(1))*(x-a(1));

I have gotten it to work in matlab fine but I dont actually understand what it is doing on a mathimatical level.

Could someone explain so I solve some errors im having with similar functions?

Thanks

Answer 1

[Stephan Ciobanu]

Hi!

a(1) % extracts the first element of array a
a(2) % extracts the second element of array a

if a is an array: with

and b, similarly, with

func is:

Answer 2

[David Hill]

It is point-slope form of a line. If the points are a=[x2, y2] and b=[x1, y1], then:

m=(a(2)-b(2))/(a(1)-b(1));%slope
func =@(x) m*(x-a(1))+a(2);%above equation seems to be wrong, should be +a(2)
func =@(x) m*(x-b(1))+b(2);%same thing just using other point