JavaScript: Round to a number of decimal places, but strip extra zeros
>>> parseFloat(0.9999999.toFixed(4)); 1 >>> parseFloat(0.0009999999.toFixed(4)); 0.001 >>> parseFloat(0.0000009999999.toFixed(4)); 0
floating-point
Floating point division vs floating point multiplication
Yes, many CPUs can perform multiplication in 1 or 2 clock cycles but division always takes longer (although FP division is sometimes faster than integer division). If you look at this answer you will see that division can exceed 24 cycles. Why does division take so much longer than multiplication? If you remember back to … Read more
Division of integers in Java [duplicate]
Converting the output is too late; the calculation has already taken place in integer arithmetic. You need to convert the inputs to double: System.out.println((double)completed/(double)total); Note that you don’t actually need to convert both of the inputs. So long as one of them is double, the other will be implicitly converted. But I prefer to do … Read more
ValueError: could not convert string to float: id
Obviously some of your lines don’t have valid float data, specifically some line have text id which can’t be converted to float. When you try it in interactive prompt you are trying only first line, so best way is to print the line where you are getting this error and you will know the wrong … Read more
How can I convert integer into float in Java?
You just need to cast at least one of the operands to a float: float z = (float) x / y; or float z = x / (float) y; or (unnecessary) float z = (float) x / (float) y;
Should I use double or float?
If you want to know the true answer, you should read What Every Computer Scientist Should Know About Floating-Point Arithmetic. In short, although double allows for higher precision in its representation, for certain calculations it would produce larger errors. The “right” choice is: use as much precision as you need but not more and choose … Read more
“f” after number
CGRect frame = CGRectMake(0.0f, 0.0f, 320.0f, 50.0f); uses float constants. (The constant 0.0 usually declares a double in Objective-C; putting an f on the end – 0.0f – declares the constant as a (32-bit) float.) CGRect frame = CGRectMake(0, 0, 320, 50); uses ints which will be automatically converted to floats. In this case, there’s … Read more
C: printf a float value
You can do it like this: printf(“%.6f”, myFloat); 6 represents the number of digits after the decimal separator.
Is it safe to check floating point values for equality to 0?
It is safe to expect that the comparison will return true if and only if the double variable has a value of exactly 0.0 (which in your original code snippet is, of course, the case). This is consistent with the semantics of the == operator. a == b means “a is equal to b“. It … Read more
Is it possible to write Quake’s fast InvSqrt() function in Rust?
I don’t know how to encode the float number using integer format. There is a function for that: f32::to_bits which returns an u32. There is also the function for the other direction: f32::from_bits which takes an u32 as argument. These functions are preferred over mem::transmute as the latter is unsafe and tricky to use. With … Read more