How can I create a for loop to count the number of letters in my array?
조회 수: 2 (최근 30일)
이전 댓글 표시
I have the following array:
bases = [ t t g c g c a t g c g c a c a ]
I want to create a for loop that loops through the array and counts the number of g’s within it.
do i use the if function?
댓글 수: 0
채택된 답변
madhan ravi
2018년 11월 20일
편집: madhan ravi
2018년 11월 20일
Stephen's way is efficient but if you insist loop then:
bases = 't t g c g c a t g c g c a c a'
ctr=0;
for i = 1:numel(bases)
if bases(i)=='g'
ctr=ctr+1;
end
end
number_of_gs=ctr
댓글 수: 16
Stephen23
2018년 11월 20일
"Basically I am trying to use the for loop created which counts the number of two elements e.g g’s and c’s, then use this for loop to calculate the GC ratio for the sequence"
So is your aim to play around with loops, or is your aim to get answers from your code?
추가 답변 (1개)
Stephen23
2018년 11월 20일
편집: Stephen23
2018년 11월 20일
The simple MATLAB solution:
>> V = 'ttgcgcatgcgcaca';
>> nnz(V=='g')
ans = 4
Or to count occurances of all of the different letters:
>> U = unique(V)
U = 'acgt'
>> histc(V,U)
ans =
3 5 4 3
I.e. 'a' occurs three times, 'c' occurs five times, 'g' occurs four times, and 't' occurs three times.
To count how many times a specific substring occurs:
>> numel(strfind(V,'gc'))
ans = 4
I.e. the substring 'gc' occurs four times.
댓글 수: 7
Stephen23
2018년 11월 20일
편집: Stephen23
2018년 11월 20일
I often edit my comments for clarity and spelling. Some comments and answers that turn out to be superfluous to the discussion I will also remove.
I notice that you have opened a new question on this topic here:
which is clearer describing what you are actually trying to achieve. You should put a link back to this thread, so that readers of that new thread know what you have already tried and what information you have been given. Otherwise people often just give you the same solutions, which is unsatisfying for everyone involved.
참고 항목
카테고리
Help Center 및 File Exchange에서 Loops and Conditional Statements에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!