How do you find the index of the first true value in a logical vector?

I need to find the index of the first 1 in a logical vector.

For example, I have a logical vector like this: V = [ 0 1 0 0 1 0 1 ] and I need a function/code that will tell me that the first true value is at index 2.

(If you can't tell from my question, I'm a beginner at Matlab.) Thanks so much for your help! I really appreciate it :)

Answer 1

[Star Strider]

Use the find function:

V1 = find(V, 1, 'first')

The find function (in its most fundamental application) locates all non-zero entries in its argument. The syntax here tells it to locate only one such value, in this instance the first one it finds, and output the index of that value.

[Jessica]

Thank you so much kind stranger!

[Star Strider]

My pleasure!

(The sincerest expression of appreciation here on MATLAB Answers is to Accept the Answer that most closely solves your problem.)

[Jessica]

Ah. Thank you for pointing that out to me.

Answer 2

[Guillaume]

find(V, 1);

find doesn't care that your vector is logical, it'll find the non-zero values anyway.

[chandra Naik]

How to find first occurrence of any integer in an array

[Velautham Daksiya]

V1=find(V==a,b,'first')

a- integer to be found

b-no of entries to be found

'first' or 'last' - from first or from last of v

[Alexander]

Thank you