Hi all, I am using the 'gaussHermite' function from the 'pracma' library ############ CODES ########### library(pracma) cc=gaussHermite(10) cc$x^2 cc$x^5 cc$x^4 ############ CODES ########### as far so good. However, it does NOT work for any NON integer values, say ############ CODES ########### cc$x^(2.5) cc$x^(-2.5) ############ CODES ########### But just think about it numberically, it should work..... why this is the case? Is there a reason for getting the "NaN"s? Thanks! ----- ###################### PhD candidate in Statistics Big R Fan Big LEGO Fan Big sTaTs Fan ###################### -- View this message in context: http://r.789695.n4.nabble.com/problem-with-Gauss-Hermite-x-and-w-tp4622115.html Sent from the R help mailing list archive at Nabble.com.
Taking negative numbers to fractional powers gives NaNs.... that's just how it works. Unless you want to use complex numbers (which R does not by default): as.complex(cc$x) ^ (2.5) Michael On Wed, May 9, 2012 at 7:22 PM, casperyc <casperyc at hotmail.co.uk> wrote:> Hi all, > > I am using the 'gaussHermite' function from the 'pracma' library > > ############ CODES ########### > library(pracma) > cc=gaussHermite(10) > cc$x^2 > cc$x^5 > cc$x^4 > ############ CODES ########### > > as far so good. However, it does NOT work for any NON integer values, say > > ############ CODES ########### > cc$x^(2.5) > cc$x^(-2.5) > ############ CODES ########### > > But just think about it numberically, it should work..... > > why this is the case? > > Is there a reason for getting the "NaN"s? > > Thanks! > > > > > > > > ----- > ###################### > PhD candidate in Statistics > Big R Fan > Big LEGO Fan > Big sTaTs Fan > ###################### > > -- > View this message in context: http://r.789695.n4.nabble.com/problem-with-Gauss-Hermite-x-and-w-tp4622115.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Hi, I know what complex number are, but I am not sure what you meant by that? ##############CODES###########> 2.5^(-2.4)[1] 0.1109032> -2.5^(-2.4)[1] -0.1109032 ##############CODES########### works fine. Negative powers mean they take the reciprocal and as far as I am concerned, real^real is just a real number. Am I mistaking something basic? Thanks. Casper ----- ###################### PhD candidate in Statistics Big R Fan Big LEGO Fan Big sTaTs Fan ###################### -- View this message in context: http://r.789695.n4.nabble.com/problem-with-Gauss-Hermite-x-and-w-tp4622115p4624395.html Sent from the R help mailing list archive at Nabble.com.