problem/limitations with atof()?

[starfire151]

In trying to convert a latitude/longitude set to floating point, I ran across a curious problem with an 18LF252 and an 18LF2525. In a test case, I formatted a string with 4 characters, a decimal point, and 4 more characters. I tried an atof() on the string and got an invalid answer. In checking other posts related to the subject, I found one that showed the only issue was precision, not validity. I tried decreasing values in the string and repeated the atof() test. It seems three digit characters before the decimal point is the limitation. Is this a real limitation? Is there a work-around or alternative solution?

My test result outputs are as follows:

string: 4329.6466 float: 34.679296
string: 329.6466 float: 329.646656
string: 29.6466 float: 29.646602
string: 9.6466 float: 9.646600
string: .6466 float: 0.646600
string: 6466 float: -2123.934719

Is this documented somewhere?

Thanks.

[Ttelmah]

atof, is listed in stdlib.h. There is no obvious reason in the listing for a problem. What compiler are you using?. There _is_ a known problem with printf, on the older compilers, if used with '%f', where garbage results are given above a certain size. What is your printf specifier?. Though it is a fault, remember that to display 4.4, requires "%9.4f" (the decimal point is a counted character), and I'd suspect it might be the output that is the problem, rather than atof.

Best Wishes

[starfire151]

I'm using version 3.249 of the compiler.

You may be right... this may be a printf() problem. I'm using %.4f format (to display 4 digits after the decimal point but allow the front end to expand to fit the number of digits in the value). Is this part of the problem?