# Search string array column for a specific string

4 views (last 30 days)
Scott Duffey on 11 Jan 2021
Commented: Scott Duffey on 11 Jan 2021
I have a 1000 x 30 string array. I'm trying to search column 5 for a specific set of strings and output the rows in which they're found.
Example Code:
I've put a sample below. I'm trying to only search column 5 of X for the terms in search and spit out which row they're in. I'm not sure how to go about this. I've tried
while i < size(search(1,:),2)
[row,col] = find(strcmp(X,search((i)));
i = i + 1;
end
but this searches the entire row and not just column 5 for the terms. I also need the rows which include other terms in addition to the search terms like the 1st row.
>> search =
1×4 cell array
{'apple'} {'banana'} {'orange'} {'grapefruit'}
>> X(1:8,1:6)
ans =
8×6 string array
"0" "0" "0" "0" "apple peanut" "0"
"0" "0" "apple" "0" "apple" "0"
"0" "0" "0" "apple" "apple" "0"
"0" "0" "apple" "0" "banana" "0"
"0" "0" "0" "0" "banana" "0"
"0" "0" "banana" "0" "orange pickle" "0"
"0" "0" "pickle" "0" "orange" "0"
"0" "0" "0" "0" "grapefruit" "0"

Ive J on 11 Jan 2021
Have you tried ismember? You only need column 5, but you fed first argument of strcmp with the whole string array.
rowIdx = find(ismember(X(:, 5), search)); % row indices of X which contain any of search elements
Scott Duffey on 11 Jan 2021
Great, thanks!

Walter Roberson on 11 Jan 2021
search = {'apple', 'banana', 'orange', 'grapefruit'}
search = 1x4 cell array
{'apple'} {'banana'} {'orange'} {'grapefruit'}
searchcol = 3
searchcol = 3
X = [
"0" "0" "0" "0" "apple" "0"
"0" "0" "apple" "0" "apple" "0"
"0" "0" "0" "apple" "apple" "0"
"0" "0" "apple" "0" "banana" "0"
"0" "0" "0" "0" "banana" "0"
"0" "0" "banana" "0" "orange" "0"
"0" "0" "pickle" "0" "orange" "0"
"0" "0" "0" "0" "grapefruit" "0"
]
X = 8×6 string array
"0" "0" "0" "0" "apple" "0" "0" "0" "apple" "0" "apple" "0" "0" "0" "0" "apple" "apple" "0" "0" "0" "apple" "0" "banana" "0" "0" "0" "0" "0" "banana" "0" "0" "0" "banana" "0" "orange" "0" "0" "0" "pickle" "0" "orange" "0" "0" "0" "0" "0" "grapefruit" "0"
[wasfound, fruitidx] = ismember(X(:,searchcol), search)
wasfound = 8x1 logical array
0 1 0 1 0 1 0 0
fruitidx = 8×1
0 1 0 1 0 2 0 0
matching_rows = find(wasfound)
matching_rows = 3×1
2 4 6
matching_fruit_number = fruitidx(wasfound)
matching_fruit_number = 3×1
1 1 2
Scott Duffey on 11 Jan 2021
Thanks! I realized I needed to be more specific. Some of the cells in column 5 contain both the search term and something else. I need to make sure I get those rows as well.