diff options
Diffstat (limited to 'lib/pure/math.nim')
| -rw-r--r-- | lib/pure/math.nim | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/lib/pure/math.nim b/lib/pure/math.nim index a8432b6f0..a1b2690a2 100644 --- a/lib/pure/math.nim +++ b/lib/pure/math.nim @@ -395,6 +395,12 @@ proc radToDeg*[T: float32|float64](d: T): T {.inline.} = ## Convert from radians to degrees result = T(d) / RadPerDeg +proc sgn*[T: SomeNumber](x: T): int {.inline.} = + ## Sign function. Returns -1 for negative numbers and `NegInf`, 1 for + ## positive numbers and `Inf`, and 0 for positive zero, negative zero and + ## `NaN`. + ord(T(0) < x) - ord(x < T(0)) + proc `mod`*[T: float32|float64](x, y: T): T = ## Computes the modulo operation for float operators. Equivalent ## to ``x - y * floor(x/y)``. Note that the remainder will always @@ -447,6 +453,7 @@ when isMainModule and not defined(JS): assert(lgamma(1.0) == 0.0) # ln(1.0) == 0.0 assert(erf(6.0) > erf(5.0)) assert(erfc(6.0) < erfc(5.0)) + when isMainModule: # Function for approximate comparison of floats proc `==~`(x, y: float): bool = (abs(x-y) < 1e-9) @@ -509,3 +516,21 @@ when isMainModule: doAssert(classify(trunc(-1e1000000'f32)) == fcNegInf) doAssert(classify(trunc(f_nan.float32)) == fcNan) doAssert(classify(trunc(0.0'f32)) == fcZero) + + block: # sgn() tests + assert sgn(1'i8) == 1 + assert sgn(1'i16) == 1 + assert sgn(1'i32) == 1 + assert sgn(1'i64) == 1 + assert sgn(1'u8) == 1 + assert sgn(1'u16) == 1 + assert sgn(1'u32) == 1 + assert sgn(1'u64) == 1 + assert sgn(-12342.8844'f32) == -1 + assert sgn(123.9834'f64) == 1 + assert sgn(0'i32) == 0 + assert sgn(0'f32) == 0 + assert sgn(NegInf) == -1 + assert sgn(Inf) == 1 + assert sgn(NaN) == 0 + |