diff options
Diffstat (limited to 'lib/pure/math.nim')
| -rw-r--r-- | lib/pure/math.nim | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/lib/pure/math.nim b/lib/pure/math.nim index 8037b31b0..cbd04a145 100644 --- a/lib/pure/math.nim +++ b/lib/pure/math.nim @@ -184,6 +184,8 @@ when not defined(JS): proc pow*(x, y: float32): float32 {.importc: "powf", header: "<math.h>".} proc pow*(x, y: float64): float64 {.importc: "pow", header: "<math.h>".} ## computes x to power raised of y. + ## + ## To compute power between integers, use `^` e.g. 2 ^ 6 proc erf*(x: float32): float32 {.importc: "erff", header: "<math.h>".} proc erf*(x: float64): float64 {.importc: "erf", header: "<math.h>".} @@ -289,6 +291,8 @@ when not defined(JS): ## echo fmod(-2.5, 0.3) ## -0.1 else: + proc trunc*(x: float32): float32 {.importc: "Math.trunc", nodecl.} + proc trunc*(x: float64): float64 {.importc: "Math.trunc", nodecl.} proc floor*(x: float32): float32 {.importc: "Math.floor", nodecl.} proc floor*(x: float64): float64 {.importc: "Math.floor", nodecl.} proc ceil*(x: float32): float32 {.importc: "Math.ceil", nodecl.} @@ -347,15 +351,19 @@ proc round*[T: float32|float64](x: T, places: int = 0): T = result = round0(x*mult)/mult when not defined(JS): - proc frexp*(x: float32, exponent: var int): float32 {. + proc c_frexp*(x: float32, exponent: var int32): float32 {. importc: "frexp", header: "<math.h>".} - proc frexp*(x: float64, exponent: var int): float64 {. + proc c_frexp*(x: float64, exponent: var int32): float64 {. importc: "frexp", header: "<math.h>".} + proc frexp*[T, U](x: T, exponent: var U): T = ## Split a number into mantissa and exponent. ## `frexp` calculates the mantissa m (a float greater than or equal to 0.5 ## and less than 1) and the integer value n such that `x` (the original ## float value) equals m * 2**n. frexp stores n in `exponent` and returns ## m. + var exp: int32 + result = c_frexp(x, exp) + exponent = exp else: proc frexp*[T: float32|float64](x: T, exponent: var int): T = if x == 0.0: @@ -364,9 +372,14 @@ else: elif x < 0.0: result = -frexp(-x, exponent) else: - var ex = floor(log2(x)) - exponent = round(ex) + var ex = trunc(log2(x)) + exponent = int(ex) result = x / pow(2.0, ex) + if abs(result) >= 1: + inc(exponent) + result = result / 2 + if exponent == 1024 and result == 0.0: + result = 0.99999999999999988898 proc splitDecimal*[T: float32|float64](x: T): tuple[intpart: T, floatpart: T] = ## Breaks `x` into an integral and a fractional part. |