Simple Way to Find How Far Down a Number Is

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Jon
Jon 2022-11-2
评论： Star Strider 2022-11-2
Hello,
I was wondering if there is a simple way to determine which row a number appears?
For example, if I have a large table with the last column is either a 1 or 0, if I want to know which row holds a 0, how can I make an array that essentially says: The value 0 appears in rows 1, 34, 89, ...
I found this forum post, which goes over how to pull a number from a column of the same row based on the value in another column.
I was thinking I could make a new column that just numbers from 1 to N (where N is the number of rows) and add that as a new column to the table.
Then using the technique from the linked forum post, save the number (value) from the added column into an empty matrix (an all-zero array from 1 to N).
Then after that, remove all the zeros and be left with an array that only has the postitions of where the 0 is in the original column.
This method seems long but it can work, I was just wondering if there is something simpler to do.
Thanks.

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Star Strider
Star Strider 2022-11-2
Ran in:
Use the find function —
T1 = array2table([rand(10,3) randi([0 1], 10, 1)])
T1 = 10×4 table
Var1 Var2 Var3 Var4 _______ _______ _______ ____ 0.63964 0.82422 0.12981 0 0.591 0.70306 0.62215 0 0.51874 0.22951 0.43027 0 0.42188 0.80246 0.65887 1 0.14287 0.80063 0.2118 0 0.73422 0.92003 0.11586 1 0.67137 0.43841 0.50498 1 0.52176 0.91758 0.3801 0 0.12744 0.61668 0.65305 0 0.45125 0.19285 0.96927 0
RowIdx = find(T1.Var4 == 0)
RowIdx = 7×1
1 2 3 5 8 9 10
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