LOG

Computes natural (base "e") logarithms.

LOG( numeric-expression )

Usage:

LN=LOG(Dt4)

PRINT "LN(";X;") =";LOG(X)

Example: LOG.BAS

Description:

The definition of natural or base "e" or Naperian logarithms is Y = LOG(X), where X = EXP(Y). "e" is an irrational number whose value is approximately 2.718 281 828 459 05.

COMPLEX Arguments

LOG accepts either a COMPLEX or REAL argument and returns a value of the same type. For COMPLEX arguments the real and imaginary parts of LOG(Z) are calculated (using real arithmetic) as

REAL(LOG(Z)) = LOG(ABS(Z))

IMAG(LOG(Z)) = ARG(Z)

which returns an imaginary part in the range -PI to PI, regardless of the current trigonometric mode. The domain of LOG includes all points in the complex plane except the origin. However, intermediate values generated during the calculation of the function can cause over or underflow errors for very large or small values of Z.

See Also:

EXP, LGT, SQRT