log (argument -- naturalLogarithm)

Inputs

• argument: Real value whose natural logarithm is taken.

Outputs

• naturalLogarithm: Natural logarithm in the same real schema.

log accepts Real32 and Real64 values. The input is dereferenced and must be non-NIL.

Behavior

• A known positive real produces the known natural logarithm in the same real schema.
• A known zero produces known negative infinity in the same real schema.
• A known negative real produces the real logarithm result, such as nanr32 for -1.0r32.
• An unknown real produces an unknown value of the same real schema.
• The result keeps the same real schema as the input.

Example

{} () {} [
  "-- real32 --" printCompilerMessage
  1.0r32 log printStack _:;
  0.0r32 log printStack _:;
  -1.0r32 log printStack _:;

  "-- real64 --" printCompilerMessage
  1.0 log printStack _:;
  0.0 log printStack _:;
  -1.0 log printStack _:;
] "main" exportFunction

Expected Output During Compilation

-- real32 --
0.0r32
-infr32
nanr32
-- real64 --
0.0
-inf
nan

See also

• ^ builtin (base exponent -- power) Raises one Real value to another of the same schema and keeps that real schema in the result.
• cast builtin (value schema -- convertedValue) Casts a Cond or numeric value to the numeric schema selected by the schema input.
• ceil builtin (value -- ceilingValue) Rounds a Real value upward and keeps the same real schema.
• cos builtin (angle -- cosine) Computes the cosine of a Real value and keeps the same real schema.
• floor builtin (value -- floorValue) Rounds a Real value downward and keeps the same real schema.
• log10 builtin (argument -- decimalLogarithm) Computes the base-10 logarithm of a Real value and keeps the same real schema.
• neg builtin (value -- negatedValue) Negates a signed Int or Real value and keeps the same schema.
• sin builtin (angle -- sine) Computes the sine of a Real value and keeps the same real schema.
• sqrt builtin (radicand -- squareRoot) Computes the square root of a Real value and keeps the same real schema.