Here is what I get from using 'fitdistr' in R to fit to a lognormal. The resulting density plot from the distribution seems to be a reason match to the data.
> x <- scan() 1: 0.80010 0.72299 0.69893 0.99597 0.89200 0.69312 0.73613 1.13559 9: 0.85009 0.85804 0.73324 1.04826 0.84002 14: 1.76330 0.71980 0.89416 0.89450 0.98670 0.83571 0.73833 0.66549 22: 0.93641 0.80418 0.95285 0.76876 0.82588 27: 1.09394 1.00195 1.14976 0.80008 1.11947 1.09484 0.81494 0.68696 35: 0.82364 0.84390 0.71402 0.80293 1.02873 40: Read 39 items > plot(density(x)) > library(MASS) > fitdistr(x, 'lognormal') meanlog sdlog -0.13480636 0.19118861 ( 0.03061468) ( 0.02164785) > lines(dlnorm(x, -.1348, .1911), col='red') On Sat, Apr 4, 2009 at 8:30 AM, Abelian <abelian1...@gmail.com> wrote: > Dear ALL > I have a list of data below > 0.80010 0.72299 0.69893 0.99597 0.89200 0.69312 0.73613 1.13559 > 0.85009 0.85804 0.73324 1.04826 0.84002 > 1.76330 0.71980 0.89416 0.89450 0.98670 0.83571 0.73833 0.66549 > 0.93641 0.80418 0.95285 0.76876 0.82588 > 1.09394 1.00195 1.14976 0.80008 1.11947 1.09484 0.81494 0.68696 > 0.82364 0.84390 0.71402 0.80293 1.02873 > all of them are ninty. > Nowaday, i try to find a distribution to fit those data. > Firstly, I normalize the data, i.e.. (x-mean(X))/(sd(X)) > i utilize the SAS to fit my data. Then i obtain the result below > ##------------------------------------------------------------------------------------------------------------- > Parameters for Lognormal > Distribution > > Parameter Symbol > Estimate > > Threshold Theta > -1.51062 > Scale > Zeta 0.237283 > Shape Sigma > 0.593481 > > Mean > 0.001321 > Std > Dev 0.982435 > ##------------------------------------------------------------------------------------------------------------------- > however, i confuse about the threshold parameter.. > How to get it? Does it be able to be calculated by R? > Thanks a lot...... > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.