Re: [R] Deriving Samples from specific, not implemented PDF for a QQ-Plot

2009-04-01 Thread David Winsemius
I am puzzled to hear that repeating only plotting give different results, if there were no further simulations. Both rt() and sample() should give different results from call to call, so if either of those functions were repeated, then varying results *should* occur. If that is not the source of th

Re: [R] Deriving Samples from specific, not implemented PDF for a QQ-Plot

2009-04-01 Thread Arndt Zimmermann
David, thank you very much for the quick response: The "sample" example helped and works fine for me. I'm sorry for not providing an example. In order to explain my problem see following example: test<-rt(1000,df=5) Repeat only the following code to see how the second and third plot cha

Re: [R] Deriving Samples from specific, not implemented PDF for a QQ-Plot

2009-03-31 Thread David Winsemius
On Mar 31, 2009, at 11:53 AM, Arndt Zimmermann wrote: this is my first post to the R-help, so please don't be too strict. Reproducible examples should not be too much to expect, since that is requested in the posting guide and multiple other locations. My problem concerns a QQ-Plot: I

[R] Deriving Samples from specific, not implemented PDF for a QQ-Plot

2009-03-31 Thread Arndt Zimmermann
Dear All, this is my first post to the R-help, so please don't be too strict. My problem concerns a QQ-Plot: I want to show how well empirical samples match with a theoretical distribution. The theoretical distribution has got several parameters, but I made it to fit via ML. Anyway