Read characters from a txt file

Hello everyone. I have a txt file in which the word 'HELLO' is written. I want Matlab to read this from the text and give me a matrix of the ASCII numbers of the letters. I found and executed the following code from a video.

fid = fopen('input1.txt');
matrix = fscanf(fid,'%f %c', [1,inf])

In the 2015 Matlab version, it gives me a matrix with 9 columns. In 2020 trial version I am using it gives the following error:

"Invalid file identifier. Use fopen to generate a valid file identifier." even though I used fopen.

Any help is appreciated.

[dpb]

The working directory isn't the same between the two installations -- the input file isn't being found in R2020x.

Just because you call fopen doesn't mean it is always successful...check the return code and error message it returns--

[Nazli Demir]

Thank you, I will check those. I still don't understand why the five letter word yields a result of 9 columns though.

[dpb]

'Pends on just what is in the file and the encoding used...for one thing also, your format string includes a '%f' for a floating point value which doesn't match the file content you described.

NB: '%c' returns any single character, including white space.

Probably what you really want is

matrix = fscanf(fid,'%s',1);

to return the word as char() string (which internally is an array of characters)

Again presuming the text is all that is in the file...

[Nazli Demir]

Writing '%s' did reduce it the number of outputs to five as I wanted. They're still not the ASCII character of the letters, but maybe I need to do something else for that. Thank you..

[dpb]

double()

after you read the input data.(*)

If you're going to use formatted read, the i/o formatting libraries return the type of the variable expected in the format string--and a text value in a text file is interpreted as character data. The floating point (or decimal, too, for that matter) format string won't recognize anything other than a valid number as a number; that's its purpose and sole mission in life.

You can cheat and read the file as straight binary bytes by using fread, but that is also system-dependent in what created the file as far as encoding may be for unicode, etc., ...

(*) The other idiom you may see is

v=s+0;

where s is the char() string and v the numeric values...MATLAB will silently do the conversion with the arithmetic operation of char() to double().