matlab returns different result for same inputs

hi

i am writing a code. the result is different when i pass varibles to it and when i pass numbers. for axample the value for x in my code is: -0.0424

now when i run this code:

max(min(((x-a)/(b-a)),((c-x)/(c-b))),0)

ans =

0.3159

and when i replace varible x with its value and run this code:

max(min(((-0.0424-a)/(b-a)),((c+0.0424)/(c-b))),0)

ans =

0.3107

the values for a,b and c are the same in both codes.

how can i fix this?

Answer 1

[Star Strider]

You may believe that the value of ‘x’ and the value of ‘x’ that are displayed are the same. They are likely much different, since ‘x’ exists with full precision internally. If you are only seeing four digits of it, you are definitely not seeing all of it. See the discussion on Floating-Point Numbers and the format function for details.

If you use:

format long

and then copy and paste the value for ‘x’ that you then see displayed, there will be very little if any discrepancy between using ‘x’ and using the displayed value of ‘x’.

[navi mahmoo]

thank you very much. that realy helped me...

[Star Strider]

As always, my pleasure!