Here is a self-contained example of my problem. set.seed(100) x = rbeta(100, 10.654, 10.439) # So the shape parameters and the exteremes are a = 10.654 b = 10.439 xmax = 1 xmin = 0 # Using the non-standardized form (as in my application and this shouldn't make any difference) of the # Beta density function, I specify the integrand (i.e., xf(x)) as integrand = function(x) {x*((1/beta(a,b))*((x^(a - 1)*(xmax - x)^(b-1)) / xmax^(a + b - 1)))} # Say I want to integrate in the range (0, 0.45) and then in (0.45, Inf) # In (0, 0.45) integrate(integrand, lower = 0, upper = 0.45)$val [1] 0.1176079
# In (0.45, Inf) integrate(integrand, lower = 0.45, upper = Inf)$val Error in integrate(integrand, lower = 0.45, upper = Inf) : non-finite function value The same thing happens when I integrate f(x) only. Thanks again. -- View this message in context: http://r.789695.n4.nabble.com/numerical-integration-and-non-finite-function-value-error-tp3618486p3619761.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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.