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rmedian

How to make mean with small numbers in a list

I have a list of small numbers :

pval.vec <- c(7.777067e-12, 8.345999e-16, 4.341658e-17, 5.984561e-15 ,1.711345e-15)

When I apply the mean of this list :

cat(sprintf("le mean value est %f",median(pval.vec)))

It gives me a result => 0.000000

I need to have a value with (nbr)e-(exposant)

Solution

  • The %f format is for “fixed point” decimal notation. Default is 6. That's why you are getting 0.000000.

    You can try to use %e for exponential. 

     # Data
 pval.vec <- c(7.777067e-12, 8.345999e-16, 4.341658e-17, 5.984561e-15 ,1.711345e-15)

 cat(sprintf("le mean value est %e",median(pval.vec)))
 #le mean value est 1.711345e-15


 #One can specify number of digits after decimal. e.g. for 2 digits
 cat(sprintf("le mean value est %.2e",median(pval.vec)))
 #le mean value est 1.71e-15