How do I record the location of a specific value in a set of data?

Hello,

I am very new to matlab, and would appreciate advice!

I understand my question is not entirely clear. So I am trying to go through data that looks like:

[1] 0 0 0 0 1 0 1 0 0

And want the code to index until it encounters the first 1 (ignoring the rest of the 1s repeated in the row) then state the distance from the start of the row to the first 1 [so here it would be the distance from column 5 to column 1]

Then ideally it would repeat the same thing for a second row. My 'for' loop is not working, and ideally this code would work for dozens of rows of data. Thank you :)

Answer 1

[madhan ravi]

First_1 = find(x,1) % where x is your row in the loop 
Distance = diff(find(x,2))

[Madison Castellanos]

So your answer really worked well for one row, and returns the answer as "5" which is correct, but how do I get it to iterate through several rows?

x2=0 0 0 1 0 0 0

0 1 0 0 0 0 0

0 0 0 0 0 1 0

But if I type

Last=find(exp,3) %so find the non zero values for all three rows, then it returns

Last=

5

10

18

Which is challenging, as I was hoping to get the positions of the 1's in their columns

so for x2 how would i create a loop to return instead?

• first non zero value is in row 1, col 4
• second non zero value is in row 2, col 2
• third non zero value is in row 3, col 6

[madhan ravi]

That is why I specifically commented saying “row” which is “singular”. Loop through through the rows. Preallocate distance as a cell.

[Madison Castellanos]

here is my attempt

x=1; %represents number of rows

Distance=cell(3,1); %preallocating distance as an empty cell

for x=1:3 %since only 3 rows in 'exp'

First_1 = find(exp,x); % where x is your row in the loop

if First_1 < 7 %(for 7 columns, but I know this isn't right)

x=x+1

Distance = diff(find(exp,2))

end

end

So I know this code is not correct, but I am still encountering the same error as earlier. Any insight would be appreciated

Answer 2

[Vladimir Sovkov]

a=[0 0 0 0 1 0 1 0 0];
k=find(a==1,1)

[Madison Castellanos]

thank you :)