find out in which row an element is equal to a specific number

hi,

I have the following problem:

I have a matrix with 20 columns and over 200'000 rows. somewhere in this matrix there seems to be some strange datas which I would like to delete. If I am looking for the rownumbers where the value is higher than a specific value, lets say I am looking for all the values in the first row that are larger than 1500

If I do this:

data18(:,1)>1500

I get a logical array, but what I am looking for is the exact row number, what do I need to do?

Answer 1

[James Tursa]

If you are looking for rows where any value is > 1500, then

find(any(data18>1500,2))

Or if you are only interested in rows where the 1st column is > 1500, then

find(data18(:,1)>1500)

[Locks]

thanks

[MAHMOUD ALZIOUD]

why do you put number 2 in the code? find(any(data18>1500,2))

[James Tursa]

The 2 forces the any( ) function to work on the rows instead of the columns (which is the default).

[BN]

Thank you from 2020. +1

Answer 2

[Youssef Khmou]

hi try :

 [x,y]=find(data18(:,1)>1500);

[Locks]

thanks!

Answer 3

[N/A]

How would you implement this in a loop for a variety of values?

Answer 4

[partha sarkar]

how to check whether aparticular value in a array is euqal to a given value