Same code line works outside but not inside for loop.

I have a code which i don't understand why acts differently outside compared to inside a for loop.

With this code:

filename = ('elspot-prices_2019_hourly_nok – Kopi.xlsx');
[~,~,raw] = xlsread(filename);
hourValues{1} = raw(any(strcmp(raw(:,2),["00 - 01"])>0,2),14);
hourValues{2} = raw(any(strcmp(raw(:,2),["01 - 02"])>0,2),14);
hourValues{3} = raw(any(strcmp(raw(:,2),["02 - 03"])>0,2),14);

I'll get the result: hourValues 1x3 cell, where each cell have an array of hour values.

I need this for 24 hours, so a loop would be great. But when like this:

for i=0:23
    if i < 10
        text1 =  "0" + string(i);
    else
        text1 = string(i);
    end
    
    if i+1 < 10
        text2 = "0" + string(i+1);
    else if i+1 == 24
            text2 = "00";
        else
            text2 = string(i+1);
        end
    end
fulltext = text1 + " - " + text2;
hourValues{i+1} = raw(any(strcmp(raw(:,2),[fulltext])>0,2),14); %<--Why don't this line work?
end

i'll get: hourValues 1x24 cell which all is empty. Just showing [] in each of the cells.

(I've tried all kinds of combination for variabel fulltext, with and without [ ], and also both as string or char.)

Any idea why this don't work?

(Edit: xlsx file added)

[Benjamin Großmann]

Please upload the corresponding xlsx file.

[Scott MacKenzie]

Yes, including the xlsx file would help.

I do see some issues in your code, however.

If you want to pad a string left with zeros, you don't need if-else statements. For example, you can replace

    if i < 10
        text1 =  "0" + string(i);
    else
        text1 = string(i);
    end
    

with

    text1 = sprintf('%02s', string(i));

[dpb]

Without a copy of the file, it's hard to say -- but that looks like very convoluted way to approach the problem from the git-go.

I'd recommend use readtable, converting the date strings to datetime and then process; much simpler to do comparisons than text/string processing.

Attach a sample input file...

[Rudolf]

Now file is included. :)

I like your code Scott, but for some reason i get a string from the if-else statement, while a char from your code. Maybe string/char both works for all purposes anyway so i shouldn't pay attention to that?

[Rudolf]

Thanks for reply Scott and dpb.

@dpb Will see if i can learn how to convert to datetime and use readtable. It sounds more convenient.

Answer 1

[Benjamin Großmann]

The problem is, that the xlsx file contains protected spaces ( char(160) ) and you are comparing to normal spaces.

Quick and very dirty solution is:

fulltext = text1 + char(160) +  "-" + char(160) + text2;
hourValues{i+1} = raw(any(strcmp(raw(:,2),[fulltext])>0,2),14); % should work now

@dpb mentions it in the comments and I would recommend it too: Use readtable and convert your xlsx data to datetime.

[Rudolf]

Thank you very much Benjamin! I didn't know about that, nice to learn.