How to find the time of event?

Hi! I have a matrix with two columns. The first column is time and the second one is events consisted of 0 and 1 only. I would like to know the time when the event (1) happend. How can I do this?

As an example, the matrix is:

0                   0
2.53164556962025    0
5.06329113924051    0
7.59493670886076    0
10.1265822784810    0
12.6582278481013    0
15.1898734177215    0
17.7215189873418    0
20.2531645569620    0
22.7848101265823    1
25.3164556962025    1
27.8481012658228    1
30.3797468354430    1
32.9113924050633    1
35.4430379746836    0

In the end I want to get an answer about what time the first 1 appeared. So for this example it should be:

ans = 22.7848101265823

Thanks for any help!

Answer 1

[Tommy]

For this sample matrix:

>> matrix = [cumsum(10*rand(25,1)), rand(25,1) < 0.1]

matrix =

    2.6774         0
    3.9889         0
   10.7113         0
   13.0342         0
   13.4335         0
   13.8455         0
   23.4376         0
   27.3937         0
   33.0231         0
   33.0414         0
   33.1545         0
   35.4013         0
   45.2526         0
   48.8322         0
   49.7725         0
   56.3409    1.0000
   64.5214         0
   66.0233         0
   74.9418         0
   80.0405         0
   87.4213         0
   92.1971         0
   96.8440    1.0000
  106.2857         0
  107.8732         0

The following works:

>> t0 = matrix(find(matrix(:,2),1),1)

t0 =

   56.3409

[Daria Ivanchenko]

Thank you very much!