str2double / str2num / conversion confusion

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?

Answer 1

[Joseph Cheng]

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

[Golnar]

How right you are!

[Golnar]

Yet for one of the parameters it still results NaN