How to Count occurrences?

Given a text: ‘tagtacagccagtagagttgattccaaggaagtccggctgttgtagagtagc’ and a three-character target pattern (for example: ‘TAG’ ), your program should identify all target patterns in the text and output the number of occurrences of the target pattern.

Sample output Text:tagtacagccagtagagttgattccaaggaagtccggctgttgtagagtagctag

Target:TAG

Number of TAG:5

Target:tag

Number of tag:5

Target:GTa

Number of cag:2

Target:exit Program terminated!

[Guillaume]

So? It's trivial to do with strfind in just one short line of code.

What effort, if any, have you made?

[Cre'Shawn Dabney]

Hello, I am confused about the looping and case sensitivity part. In other words I can perform the first output which is

Text:tagtacagccagtagagttgattccaaggaagtccggctgttgtagagtagctag

Target:TAG

Number of TAG:5

But I cant seem to produce the rest of the outputs. This is what I used to produce the first output:

clear;clc;

text=input('Enter text:','s');

pattern=input('Target:','s');

count=0;

n=size(text,2);

m=size(pattern,2);

for i=1:n-m

%sunstring find

temp=text(i:i+m-1);

%comapre

if(strcmp(temp,pattern))

count=count+1;

end

end

fprintf('Pattern count: %d\n',count);

[Priyadharshini A.R]

Hello Dabney,

The loop must go on till n-m+1 so that it can traverse till last element in text

Answer 1

[Jan]

t = 'tagtacagccagtagagttgattccaaggaagtccggctgttgtagagtagc';
tag = 'tag';

result = sum(strfind(lower(t), lower(tag)))

Answer 2

[Alaster Meehan]

strcmpi ignors case

Cheers Alaster

[Cre'Shawn Dabney]

Thank you for your answer. I am still confused on how to write this code. Could you possibly demonstrate how? If not thank you so much for your participation!