Creating new vector and using IF correct or loop?

Hello,

I need some help with my matlab code.

I have two vectors of data: "position" and "time", The position vector has a maximum value of ~2 and a minimum value of ~-1. Booth vector are of 1x500000 points. My time vector looks like this: time=(0:length(position)-d)*dt %dt is the value between each point (2e-4), delta time

I want to be able to construct a new vector called "force".

This vector should be created by multiplication the position vector with a certain value. But I have different values for this multiplication. If the current value of the position is lower than 0.5, it should be multiplied with a certain value, x If it is between 0.5 and 1.5, it should be multiplied with a value, y. And so on...

I should then also be able to plot "time" vs "force".

I guess I should use some if and/or elseif commands. But how do I get it right?

Thank you.

[Image Analyst]

Make it easy for people to help you by attaching a data file and a snippet of code to read it in to some variables.

Answer 1

[Adam]

Just put together a multiplication vector as e.g.

multVec = zeros( size( position ) );

multVec( position < 0.5 ) = m1;
multVec( 0.5 <= position & position < 1.5 ) = m2;
...

Then:

force = position .* multVec;

[Daniel]

Thank you Adam, It works fine!

Answer 2

[Andrei Bobrov]

v = [-inf,.5,1.5,inf];
[~,ii] = histc(position,v);
m = [2 8 15]'; % example as m = [m1,m2,m3];
force = m(ii).*position;

[Daniel]

Thank you, very helpful.