how to extrapolate information from two columns?

So I'm trying to extrapolate some informations from two columns at a certain time to find a postion.

A = [time ; x ; y]

hit = 4

example

[A] = [ 1, 1.5, 2, 2.75, 3.5, 6;

55, 39, 32, 28,16,10 ;

12, 19, 25, 32, 22, 14]

I know you need to sort the first row, time, to figure out which columns to use.

[~,col1] = find(A(1,:)<hit,1) %to find the column before hit

[~,col2] = find(A(1,:)>hit,1) %to find the column after hit

not sure if I'm using this, right currently stuck here. I forgot what the error was and can only access matlab at school.

but col1 should = 5 and col2 = 6

but after that, I want use a extrapolation formula to find a new x and y

using

newpostion = postion1 + ((postion2-postion1)/(time2-time1))(hit-time1)

so I get,

xnew = A(2,col1) + ((A(2,col2)-A(2,col1))/(A(1,col2)-A(1,col1)))(hit-A(1,col1))

ynew = A(3,col1) + ((A(3,col2)-A(3,col1))/(A(1,col2)-A(1,col1)))(hit-A(1,col1))

doing it by hand, I got xnew = 14.8 and ynew = 20.4

Answer 1

[Jonas]

i suggest to use the interp1() function twice, once with time and x and once with time and y. you can give the query point to each call of the interp1() function

[NotGood]

This is a good idea, I will try it as soon as I can. I would of never know about that function.