How do I find the percentage of a number of values within a decimal range?

I would like to know the percentage of values which lie within a certain range e.g 0.500000 and 0.00000. where 0.000000=100% and 0.500000=0%. i've tried using:

 percent=sum(x <= 0.500000 & x >= 0.000000) / numel(x)  %number of values between 0.000000 and 0.500000 divided by total number. x was from other process before this codes. its a decimal between those range.
set(handles.percentbox,'string',percent);

and the output is always 1. how to fix this?

[Jan]

The question ist not clear. Does

sum(x <= 0.500000 & x >= 0.000000) / numel(x)

give you the wanted result? Then is it only a problem of the display in the GUI?

Has "percent" been defined with integer type before, such that the assigned value is rounded?

I cannot imagine what "0.0=100% and 0.5=0%" means. If you are looking for the relation of the values inside a range, it is not meaningful to assigne percentage values to the limits.

[Cam Salzberger]

Frequently in this kind of situation, it helps to divide up the problem. What do you get when you just do:

x = [0 0.25 0.5 0.75 1];
percent = nnz(x <= 0.5 & x >= 0) / numel(x);
disp(percent)

or look at your "percent" variable in the Variable Browser. This will tell you if you are calculating "percent" in the way that you want to. I'm really not sure what you mean by 0.000000=100% and 0.500000=0%.

Once you determine that you are calculating "percent" correctly, you can then try to put it into the uicontrol. As Walter said, you'll want to multiply by 100 if you want a true percentage. As J Smith said, you'll want to convert the number to a string before setting it to the String property of a uicontrol.

If that's not working, try opening the GUI in GUIDE, and hard-coding the value in there. Does that work as expected? You can also try specifying precision with more control using either:

num2str(percent,'%.2f')

or

sprintf('%.2f',percent)

So what are you getting for disp(percent)?

Answer 1

[ES]

This looks fine to me except the second line.

set(handles.percentbox,'string', num2str(percent));

what is your x?

[Stella Gareth]

x value could be any decimal between those range. like 0.322356, 0.196783 etc. anyway i've tried your line and the output still 1. is it caused by a decrement range? ah how to explain it. like in this case, the lower the value, the higher the percentage. but maybe the system gets it like 0.000000 is the lowest value or the 0% and 0.50000 is the 100%, which is wrong. any idea?

[Stella Gareth]

up

[Jan]

up what?

Answer 2

[Walter Roberson]

set(handles.percentbox,'string', 100-100*mean(x>=0 & x<=1/2) )

[Stella Gareth]

still wrong output, now its 0.

Answer 3

[Jan]

With some guessing:

% 0.0 => 100%, 0.5 => 0%
x = [0, 0.38, 0.5];
p = (0.5 - x) * 2 * 100;   % or 100 - 200 * x
set(handles.percentbox,'string', num2str(percent));

If this helps, I cannot avoid to mention that this is very elementary maths and the formulation of the question was misleading.