This function extends FORTRAN's generic log10 function to evauate the principal value of the complex common logarithm.

Function Return Value

LOG10 — Complex function value.   (Output)

Required Arguments

Z — Complex argument for which the function value is desired.   (Input)

FORTRAN 90 Interface

Generic:                              LOG10 (Z)

Specific:                             The specific interface names are CLOG10 and ZLOG10.

FORTRAN 77 Interface

Complex:                            CLOG10 (Z)

Double complex:               The double complex function name is ZLOG10.

Description

The function LOG10(Z) evaluates log10 (z) . The argument must not be zero, and |z| must not overflow.

Example

In this example, the log₁₀(0.0076i) is computed and printed.

 

      USE LOG10_INT

      USE UMACH_INT

 

      IMPLICIT   NONE

!                                 Declare variables

      INTEGER    NOUT

      COMPLEX    VALUE, Z

!                                 Compute

      Z     = (0.0, 0.0076)

      VALUE = LOG10(Z)

!                                 Print the results

      CALL UMACH (2, NOUT)

      WRITE (NOUT,99999) Z, VALUE

99999 FORMAT (' LOG10((', F7.4, ',', F7.4, ')) = (', &

              F6.3, ',', F6.3, ')')

      END

Output

 

LOG10(( 0.0000, 0.0076)) = (-2.119, 0.682)

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