How can I repeat the code for multiple timesteps?

Hi, I need to write a code to let a particle move multiple timesteps, where the timesteps can be any number (e.g. 2 or 50). The situation is the following, I have an array where a x-coordinate, an y-coordinate and the direction are in:

Q =

     1     2     1
     1     3     1
     3     3     2
     3     1     1
     2     3     2

To make it easy, x and y can be 1, 2 or 3 and the direction can be 1 or 2. The direction I have defined as:

if Direction == 1 %If the direction ==1 then x stays equal but y becomes 1 higher
    x = x
    y = y + 1
end
if Direction == 2 %If the direction ==2 then y stays equal but x becomes 1 higher
    x = x + 1
    y = y
end

But how can i let this repeat for multiple time steps, because, like the code above is now, this should happen in one timestep where this timestep (dt) is set.

Answer 1

[Walter Roberson]

for stepnum = 1 :  100
.... your existing lines
end

[Danny Helwegen]

Matlab doesn't recognises stepnum, do i first have to define this?

[Walter Roberson]

It is a for loop. for acts like a repeated assignment statement.

You can use whatever variable name is convenient for your purposes. For example,

for timestep_number = 1 : 100
    ... your existing lines
end

You could also use

for time = 0 : 0.01 : 5
    .... your existing lines
end

but in practice it is usually easier to iterate over step numbers than to iterate over times if you need to record data as you go along.