如何读取在Matlab中的字符串变量中出现的预定字符的编号

Question

I process a big file with Matlab. In each line of the input file, data are separated with dots " . ". Due to poor format, the number of dots may change line by line of the input file.

For example:

line1 = 'DIDYMOTE.150.L20'
line2 = 'N.ELBETI.150.L10'

How can I read the number of dots that appear in each line ?

Answer 1

In matlab everything is an array. So

data = load('file.txt');
[no_lines, no_characters] = size(data);

for i = 1 : no_lines
    no_dots[i] = 0
    for j = 1 : no_characters
         if data[i][j] == '.'
             no_dots[i] = no_dots[i] + 1
         end
    end
end

However, matlab has no strings, and is very unsuitable for handling text data. If any of the lines has different length you will get an error. Even if this is not the case, you are better off using another language for this. It will take you less time to learn how to process text in Python (for example), than trying to fit your problem into matlab.