Loops in Matlab

I have a dataset which contains a number in column one and a number in column two. I am trying to make a loop which iterates through each row to check to see if any of the rows contain a specific number, if so the Variable 'Access' = 1, else 'Access' = 2

This code is not working, any help would be very much appreciated.

i=length(Day2)
t=0
while (t < i)
t = t+1
if (Day2(t,:) == [50.3779, -4.1227])
Access=1;
else
Access=2;
end
end

Answer 1

[Oleg Komarov]

Day2(t,:) == [50.3779, -4.1227]

How did you get those values? If you simply copy pasted the results from teh command window, then you probably missed the fact that the display truncates numbers.

try:

format long g

and then retrieve your values again.

I would go for smt like this:

idx = (Day2(:,1) > 50 - tol & Day2(:,1) < 50 + tol) &...
      (Day2(:,2) > -4 - tol2 & Day2(:,2) < -4 + tol2)

So you just need to set the tolerances accordingly

Oleg

Answer 2

[Matt Tearle]

When you say dataset, I take it that you don't mean a dataset array. So:

x = (Day2(:,1)==50.3779)&(Day2(:,2)==-4.1227);
Access = 2-any(x);

But be careful with == with floating-point values. It might be better to do

x = (abs(Day2(:,1)-50.3779)<tol)&(...);