Round off Errors in LabWindows/CVI

[jthoriuchi]

I have a double precision variable, which is initially set to 1.0.  In a while loop (while x < 1.7) , I add 0.1 to it:  x = x + 0.1.  When I get to x = 1.6, x becomes 1.700000001.  This causes my loop to prematurely terminate. 

Is there anyway around this?   

[msaxon]

Floating point representations are not, in general, exact and you must allow for some error in the representation. For an iterative loop such as you have, it might be better to use an integer control variable:

for (i=0;i<7;i++)
{
    double x=1.0 + 0.1*i;
    ...
}

or alternatively, you must allow for some error in the representation:

for (x=1.0; x<1.75;x+=0.1)
{
   
}