| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Numeric.Logarithms
Synopsis
- log2Floor :: (HasCallStack, Real a) => a -> Int
- log2Ceiling :: (HasCallStack, Real a) => a -> Int
- log2Approx :: (HasCallStack, Real a) => a -> (Int, Ordering)
- log2With :: (HasCallStack, Real a) => (Int -> Ordering -> Int) -> a -> Int
- ilog2Floor :: (HasCallStack, Integral a) => a -> Int
- ilog2Ceiling :: (HasCallStack, Integral a) => a -> Int
- ilog2Approx :: (HasCallStack, Integral a) => a -> (Int, Ordering)
- ilog2With :: (HasCallStack, Integral a) => (Int -> Ordering -> Int) -> a -> Int
Real Logarithms
log2Floor :: (HasCallStack, Real a) => a -> Int Source #
Returns the floor of the base-2 logarithm of a Real argument.
log2Ceiling :: (HasCallStack, Real a) => a -> Int Source #
Returns the ceiling of the base-2 logarithm of a Real argument.
Advanced
log2Approx :: (HasCallStack, Real a) => a -> (Int, Ordering) Source #
Returns an approximate base-2 logarithm of the argument.
The returned Int is one of the two nearest integers to the exact result,
and the returned Ordering tells whether the exact result is greater than,
equal to, or less than the Int. LT means the exact result is less than
the rounded result.
This effectively gives results like "between 7 and 8" and leaves it up to
the caller to decide how (or whether) to round the result. See also
log2With for a version that will always round, but leaves the particular
rounding strategy up to the caller.
log2With :: (HasCallStack, Real a) => (Int -> Ordering -> Int) -> a -> Int Source #
Returns the base-2 logarithm with custom rounding.
The first parameter is a rounding adjustment function: given the approximate
result and an Ordering indicating its relation to the exact result, return
the rounded result.
This could be useful if you want something other than floor or ceil, e.g. round-towards-0, round-towards-even, etc.
Integer Logarithms
ilog2Floor :: (HasCallStack, Integral a) => a -> Int Source #
Returns the floor of the base-2 logarithm of an Integral argument.
ilog2Ceiling :: (HasCallStack, Integral a) => a -> Int Source #
Returns the ceiling of the base-2 logarithm of an Integral argument.
Advanced
ilog2Approx :: (HasCallStack, Integral a) => a -> (Int, Ordering) Source #
Returns the approximate base-2 logarithm of an Integral argument.