Subscripts and Fractions in Fortran 95

[kathrynag]

i'm trying to write the equation dB=log_10(P_2/P_1)
I just need help writing this equation into Fortran.
I know for exponents I use **, but what about subscripts?
Also, my inital thought for a fraction is /. Is this correct?

 

[kathrynag]

Do I use 10 log(P2/P1)

 

[mathmate]

In fortran, subscripts mean the index of an array.
For an array such as
REAL*8 P(10)
P(1) is the equivalent as what we write as P₁, and so on.
So what to write depends on how your variables have been defined.
If you write

REAL*8 P(2), B
P(1)=20
P(2)=40
B=LOG10(P(1)/P(2))

will be perfectly OK.