JavaScript Math Expression Yields Different Results

Question

The following is a line I have in my Javascript code. It outputs -5108024 and some change when sqftVal = 2828 and bathsVal = 3.5 .

out.value = -6932000 + 221400 * Math.log(sqftVal) + 637.2*Math.exp(bathsVal) + 51640; 

However, when I manually type this in my calculator, I get roughly -5099721 and some change. I get the same result in R . Why does JavaScript mess up the math, and what can I do to fix this?

Calculator/R input: -6932000 + 221400 * ln(2828) + 637.2 * e^(3.5) + 51640 = -5099721.073

I don't believe this is a floating point error because as I add more terms, the difference becomes fairly large.

Plus, everything was matching up until I added the fourth term ( +51640 ) which made no sense to me.

Answer 1

There must be some other code that is interfering with your values or something, because the code shown does not produce the value you report.

 var sqftVal = 2828; var bathsVal = 3.5; var value = -6932000 + 221400 * Math.log(sqftVal) + 637.2*Math.exp(bathsVal) + 51640; console.log(value);