How to extend a best fit line?

Hi, I divided the datapoints of a fault scarp profile into three datasets for the footwall, scarp slope and hanging wall and plotted the respective best fit lines. What is the easiest way to just extend the length of the best fit line for the scarp so that it crosses the best fit lines of the footwall and the hanging wall?

Answer 1

[KSSV]

P1 = rand(2,1) ;
P2 = rand(2,1) ;

% line(P1,P2)
plot([P1(1) P2(1)],[P1(2) P2(2)],'b','linewidth',5)

%%Extend line 
m = (P2(2)-P1(2))/(P2(1)-P1(1)) ;  % slope of line 
N = 100 ; 
x = linspace(-2,2,N) ;  % specify your x limits 
y = P1(2)+m*(x-P1(1)) ;  % y = y1+m*(x-x1) ;

hold on
plot(x,y,'.r')

[Schirin Sellmann]

Hey, thanks for your time. Took me a little while to get how to apply that to my data, but got it now! ;)

[KSSV]

Thanks is accepting the answer.....:)

[Schirin Sellmann]

Ya, but an additional 'thanks' does't hurt...esp. as I'm pretty sure that I will have to ask tons of other annoying questions here ;)

[KSSV]

You are welcome...!

[Image Analyst]

Schirin, can you please click the "Accept this answer" link so KSSV gets credit (reputation points) for his efforts to help you.

[Md Ashraf]

x1=302;

x2=380;

y1=1;

y2=101;

here is my point of the line . how I increase the size of this line?