After looking into this some more, it looks like signaling_NaN is useless as provided. If floating point exceptions are enabled, then calling it counts as processing a signaling NaN, so it immediately raises an exception. If floating point exceptions are disabled, then processing a signaling NaN automatically demotes it to a quiet NaN, so signaling_NaN … Read more
The binary format shouldn’t change – it would certainly be a breaking change to existing specifications. It’s defined to be in IEEE754 / IEC 60559:1989 format, as Jimmy said. (C# 3.0 language spec section 1.3; ECMA 335 section 8.2.2). The code in DoubleConverter should be fine and robust. For the sake of future reference, the … Read more
Short version: The reason it’s different is because pandas uses bottleneck (if it’s installed) when calling the mean operation, as opposed to just relying on numpy. bottleneck is presumably used since it appears to be faster than numpy (at least on my machine), but at the cost of precision. They happen to match for the … Read more
2 ways to solve this: You can solve this by replacing A *= B with A = (A * B) or with numpy.multiply(A, B, out=A, casting=’unsafe’)
Using math.Float32bits and math.Float64bits, you can see how Go represents the different decimal values as a IEEE 754 binary value: Playground: https://play.golang.org/p/ZqzdCZLfvC Result: float32(0.1): 00111101110011001100110011001101 float32(0.2): 00111110010011001100110011001101 float32(0.3): 00111110100110011001100110011010 float64(0.1): 0011111110111001100110011001100110011001100110011001100110011010 float64(0.2): 0011111111001001100110011001100110011001100110011001100110011010 float64(0.3): 0011111111010011001100110011001100110011001100110011001100110011 If you convert these binary representation to decimal values and do your loop, you can see that for float32, the … Read more
I purposefully did not compile and run then on my system, since this is the type of thing that could be compiler dependent. This is not compiler dependent. C++ clearly defines the order of these operations and how they are converted. How the conversion happens is dependent on the order of operations. double result1 = … Read more
The technically correct answer is: because no one has written impl Add<f64> for i32 {}. The cheeky answer is: because Rust doesn’t want you to shoot yourself in the foot. The longer, potentially more useful answer is… In computers, integers and floating point numbers both have a limited range, ultimately driven by the number of … Read more
Use snprintf() from stdlib.h. Worked for me. double num = 123412341234.123456789; char output[50]; snprintf(output, 50, “%f”, num); printf(“%s”, output);
Double.Parse(“1.234567E-06”, System.Globalization.NumberStyles.Float);
You ask about C++, but the specifics of floating-point values and encodings are determined by a floating-point specification, notably IEEE 754, and not by C++. IEEE 754 is by far the most widely used floating-point specification, and I will answer using it. In IEEE 754, binary floating-point values are encoded with three parts: A sign … Read more