MATLAB: Str2double / str2num / conversion confusion

str2doublestr2num

f1=fopen('report_data.txt', 'r');
f2=fopen('imaginary.txt', 'r');
area=[str2double(fgetl(f1)), str2double(fgetl(f2))]';
volume=[str2double(fgetl(f1)), str2double(fgetl(f2))]';  
healthy_exposed=[str2double(fgetl(f1)), str2double(fgetl(f2))]';
pus=[str2double(fgetl(f1)), str2double(fgetl(f2))]';
necrotic=[str2double(fgetl(f1)), str2double(fgetl(f2))]';
fprintf('Surface Area: %2.1f cm^2 \n', str2double(area(1)));
fprintf('Volume: %2.3f cm^3 \n', str2double(volume(1)));
fprintf('Necrotic: %2.3f', str2double(necrotic(1)));
fprintf('Infection: %2.3f', str2double(pus(1)));
fprintf('Exposed: %2.3f', str2double(healthy_exposed(1)));

Result:

The initial format is a string because its a line from an edit box in a GUI. But these 5 parameters are numbers. Why aren't they showing up?

Best Answer

reason is that you are doing str2double 2x. so area already has the text being converted to a double. then you try to convert a double to double in your fprintf.

simple test:

x='1';
str2double(str2double(x))

will result to NaN

no need for the str2double in the fprintf statement

Related Solutions

MATLAB: Question about fgetl(fileID)

Try

    function    ccsm()
        fid = fopen( 'cssm.txt', 'r' );
        cac = regexp( fgetl( fid ), '=', 'split' );
        patieritName = cac{2};
        cac = regexp( fgetl( fid ), '=', 'split' );
        dataofBwth = datenum( cac{2}, 'mm/ddyyyy' );
        cac = regexp( fgetl( fid ), '=', 'split' );
        heaFthy_exposed = str2double(cac{2});
        cac = regexp( fgetl( fid ), '=', 'split' );
        pus = str2double(cac{2});
        cac = regexp( fgetl( fid ), '=', 'split' );
        necrotic = str2double(cac{2});
        cac = regexp( fgetl( fid ), '=', 'split' );
        ulcer_stage = str2double(cac{2});
        cac = regexp( fgetl( fid ), '=', 'split' );
        area = str2double(cac{2});
        cac = regexp( fgetl( fid ), '=', 'split' );
        volume = str2double(cac{2});
        fclose('all');
    end

where cssm.txt contains

    patieritName = John Doe
    dataofBwth = 04/2511987
    heaFthy_exposed =75
    pus = 10
    necrotic = 15
    ulcer_stage = 3
    area = 89
    volume = 90

MATLAB: Str2double/str2num

Floating point variables do not have leading 0's physically stored in memory (not counting the denormalized numbers of course). So 0001 and 1 are stored exactly the same in memory. If you want to display the leading 0's then you need to use a format that specifies that on print out. E.g.,

>> day = '0001'
day =
0001
>> d = str2double(day)
d =
     1
>> fprintf('%04d\n',d)
0001

Best Answer

Related Solutions

MATLAB: Question about fgetl(fileID)

MATLAB: Str2double/str2num

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