On 3 Sep 2003 at 17:31, Rado Bonk wrote: ? It is not really clear what you want, since what you call the "hypsometric" curve is really the cumulative distribution function, so its integral is infinite.
Does the following help? > data(volcano) > library(stepfun) > plot(ecdf(volcano), do.points=F, verticals=T) > test <- ecdf(volcano) > str(test) function (v) - attr(*, "class")= chr [1:3] "ecdf" "stepfun" "function" - attr(*, "call")= language ecdf(volcano) > test(120) [1] 0.4586395 > args(integrate) function (f, lower, upper, subdivisions = 100, rel.tol = .Machine$double.eps^0.25, abs.tol = rel.tol, stop.on.error = TRUE, keep.xy = FALSE, aux = NULL, ...) NULL > test( 100:110) [1] 0.1066516 0.1221029 0.1371773 0.1535708 0.1727907 0.1929527 0.2127379 [8] 0.2317694 0.2534389 0.2726588 0.3060109 > integrate( test, 80, 200) Error in integrate(test, 80, 200) : maximum number of subdivisions reached > integrate( test, 80, 200, subdivisions=1000) 69.81223 with absolute error < 0.0033 > Kjetil Halvorsen > Hi R-users, > > How can I compute the area below the curve (so called "hypsometric > integral") plotted by: > > plot(ecdf(volcano), do.points=F, verticals=T) > > Thanks, > > Rado > > > -- > Radoslav Bonk M.S. > Dept. of Physical Geography and Geoecology > Faculty of Sciences, Comenius University > Mlynska Dolina 842 15, Bratislava, SLOVAKIA > tel: +421 905 968 127 e-mail: [EMAIL PROTECTED] > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help