Hi folks, I am having a question about efficiently finding the integrals of a list of functions. To be specific, here is a simple example showing my question.
Suppose we have a function f defined by f<-function(x,y,z) c(x,y^2,z^3) Thus, f is actually corresponding to three uni-dimensional functions f_1(x)=x, f_2(y)=y^2 and f_3(z)=z^3. What I am looking for are the integrals of these three functions f_1,f_2,f_3 over some interval, say, (0,1). More specifically, the integrals \int_0^1 f_1(x) dx, \int_0^1 f_2(y) dy and \int_0^1 f_3(z) dz. For this simple example, of course we can do these three integrals one by one using integrate (f_1, lower=0, upper=1) However, in practice, I have a sequence of 5000 uni-dimensional functions and hope to find all of their integrals (over some regions), so using loops to do this one by one is not efficient. A possible idea is to convert the sequence of functions to a list of objects, and use sapply() which allow us to find the integrals in a fashion of vectorizing. But I don't know how to convert the above example function f to a list. In my research problem, I can only define the 5000 functions in a vectorizing way like f<-function(x1,x2,...,x5000) c(f1(x1),f2(x2),...,f5000(x5000)) So how to convert it to a list will be a crucial step to efficiently get the integrals. Thanks for all the suggestions! Jeff -- View this message in context: http://r.789695.n4.nabble.com/efficiently-finding-the-integrals-of-a-sequence-of-functions-tp4179452p4179452.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.