I'm trying to figure out why 1e-10 is used in this code. I was running through the exercises and got stuck on Next, change the loop condition to stop once the value has stopped changing (or only changes by a very small delta). See if that's more or fewer iterations. After not figuring it out, I searched and found this solution by someone else.
In a lot of solutions, I saw 1e-10 as part of an if statement within the for loop. In Golang, does it mean that 1e is risen to the (-10) power? Is it like, automatic for Golang? So basically normally I'd assume it would be written as 1e^(-10)?
package main
import (
"fmt"
"math"
)
func Sqrt(x float64) float64 {
z := float64(2.)
s := float64(0)
for i := 0; i < 10; i++ {
z = z - (z*z - x) / (2 * z)
if math.Abs(z-s) < 1e-10 {
break
}
s = z
}
return z
}
func main() {
fmt.Println(Sqrt(2))
fmt.Println(math.Sqrt(2))
}
Thanks for any/all help one may provide!
1e-10 is a floating-point literal with the value 1 to the power minus 10.
The Go Programming Language Specification
A floating-point literal is a decimal representation of a floating-point constant. It has an integer part, a decimal point, a fractional part, and an exponent part. The integer and fractional part comprise decimal digits; the exponent part is an e or E followed by an optionally signed decimal exponent. One of the integer part or the fractional part may be elided; one of the decimal point or the exponent may be elided.
float_lit = decimals "." [ decimals ] [ exponent ] | decimals exponent | "." decimals [ exponent ] . decimals = decimal_digit { decimal_digit } . exponent = ( "e" | "E" ) [ "+" | "-" ] decimals . 0. 72.40 072.40 // == 72.40 2.71828 1.e+0 6.67428e-11 1E6 .25 .12345E+5