The formula I remember for conversion of logarithms from one base to another is this one (the subscript indicates the base).
Log10[x]/Log10[b] = Logb[x]
This derives from taking the log of both sides of
x = b^logb[x]
Taking the natural log of this equation, for example, gives
ln[x] = logb[x]*ln[b], which can also be written as
ln[x]/ln[b] = logb[x]
As you can see, I can compute the log of my value (x) in some arbitrary base (b) using any convenient logarithm function--base 10, natural log, whatever. I just need to compute the ratio of the log of my value (x) to the log of the base I want (b).
Log10[x]/Log10[b] = Logb[x]
This derives from taking the log of both sides of
x = b^logb[x]
Taking the natural log of this equation, for example, gives
ln[x] = logb[x]*ln[b], which can also be written as
ln[x]/ln[b] = logb[x]
As you can see, I can compute the log of my value (x) in some arbitrary base (b) using any convenient logarithm function--base 10, natural log, whatever. I just need to compute the ratio of the log of my value (x) to the log of the base I want (b).
