如何计算R中的对数底数为十

Question

I have a dataframe called mydf . I want to calculate -log base 10 for all the values in mydf$colx .

Answer 1

You can use either the log10(x) function or the general form log(x, base) :

-log10(100)
# [1] -2

log10(100) * -1
# [1] -2

-log(100, base = 10)
# [1] -2

log(100, base = 10) * -1
# [1] -2