string to num

Hi,

I am reading string data of this format from a text file:

(20:200,40:300)

This is the area of an image which I wish to select. How do I convert this string to number range. Thanks.

Charles-

Answer 1

[Titus Edelhofer]

Hi Charles,

a simple way would be replace all non digits by spaces and use str2num afterwards:

x = '(20:200,40:300)';
x(~isstrprop(x, 'digit')) = ' ';
xNumber = str2num(x)

Titus

[Charles]

Thanks for your response. But this only extracts all the numbers present.

[Titus Edelhofer]

That's right. But I guess xNumber(1):xNumber(2) and xNumber(3):xNumber(4) are what you are needing, aren't you?

[Charles]

yes, but the numbers could vary, i.e. 4, 47...I have to process large amount of files. Thanks for your suggestions.

[Titus Edelhofer]

Charles, I don't understand. Of course they can vary: take another x (read from your file) and you will get other numbers ...??

[Charles]

Ok, first of all, xNumber = str2num(x) gives a single number. How do you grab the individual elements of the number? xNumber(1) wouldn't return the first number.

Secondly, assuming that it does work and using the above as an example. xNumber(1) returns 2. What if the first number is 20 instead, or 202? Hope you understand.

[Sean de Wolski]

A note: you can also use RESHAPE to reshape the numbers if there are multiples.

[Titus Edelhofer]

Hi Charles, weird. When I run my code above I get a vector xNumber=[20 200 40 300] ...

[Sean de Wolski]

me too (2011b)

[Charles]

Wow, unbelievable. Thanks a lot. The error that I made is that instead of x(~isstrprop(x, 'digit')) = ' ';

I typed x(~isstrprop(x, 'digit')) = '';

i.e, no space between the ''. I had to type as the matlab is running on another pc. Answer accepted. Thanks a million.

[Titus Edelhofer]

;-) At least it proved worth doing what I once read from some other poster: please keep on asking and accept only when the question is fully answered...

[Charles]

:-) I truly appreciate your assistance. Really, thanks a lot.

[Andrei Bobrov]

str2double(regexp(x,'\d+','match'))

Answer 2

[osman]

use str2num

[Sean de Wolski]

That won't work. He'd going to need to parse the string based on '(,:' first

[Charles]

As Sean de Wolski pointed out, it doesn't work.