FORTRAN Reference Manual

Intrinsic Functions
FORTRAN Reference Manual—528615-001
8-22
LOG10 Function
•
The value returned by the LOG function in programs that specify ENV OLD might
differ slightly from the value returned by the LOG function in programs that specify
ENV COMMON. The value returned by the LOG function when you specify ENV
COMMON differs slightly because of rounding methods on the final result.
Example of the LOG Function
x = ALOG (a) + ALOG (b)
LOG10 Function
The LOG10 function returns a common (or base 10) logarithm.
The table below shows the argument and function type for the LOG10 generic function
and its associated specific functions.
Considerations
•
The value of LOG10 (x) is the number y such that
x = 10.0
y
•
The result type of the LOG10 function is the same as the type of its argument.
•
If x < 0, program execution terminates abnormally with an error message.
•
The value returned by the LOG10 function in programs that specify ENV OLD
might differ slightly from the value returned by the LOG10 function in programs that
specify ENV COMMON. The value returned by the LOG10 function when you
specify ENV COMMON differs slightly because of rounding methods on the final
result.
Example of the LOG10 Function
DOUBLE PRECISION x, a
x = DLOG10 (a)
Syntax Argument Type Function Type
LOG10 (x)
ALOG10 (x) Real Real
DLOG10 (x) Double Precision Double Precision
x is an arithmetic expression.