________________________________________
From: peter dalgaard <pdalgd at gmail.com>
Sent: 10 March 2016 09:36
To: John Hillier
Cc: r-help at r-project.org
Subject: Re: [R] truncpareto() - doesn't like my data and odd error message
Also if you simultaneously change the 2000 to say 1999?
-p
On 10 Mar 2016, at 09:22 , John Hillier <J.Hillier at lboro.ac.uk> wrote:
Thank you Peter,
I believe this might be the way the error message is hard coded (i.e. it's always y to describe the input). Anyway, I changed the first line to
pdataH <- data.frame(y = H_to_fit$Height)
This makes the input 'y' instead of 'H_to_fit.Height', but makes no difference to the outcome/error message.
John
-------------------------
Dr John Hillier
Senior Lecturer - Physical Geography
Loughborough University
01509 223727
________________________________________
From: peter dalgaard <pdalgd at gmail.com>
Sent: 09 March 2016 19:58
To: John Hillier
Cc: r-help at r-project.org
Subject: Re: [R] truncpareto() - doesn't like my data and odd error message
On 09 Mar 2016, at 18:52 , John Hillier <J.Hillier at lboro.ac.uk> wrote:
Dear All,
I am attempting to describe a distribution of height data. It appears roughly linear on a log-log plot, so Pareto seems sensible. However, the data are only reliable in a limited range (e.g. 2000 to 4800 m). So, I would like to fit a Pareto distribution to the reliable (i.e. truncated) section of the data.
I found truncpareto(), and implemented one of its example uses successfully. Specifically, the third one at http://www.inside-r.org/packages/cran/vgam/docs/paretoff (also see p.s.).
When I try to run my data, I get the output below. Inputs shown with chevrons.
pdataH <- data.frame(H_to_fit$Height)
summary(pdataH)
H_to_fit.Height
Min. :2000
1st Qu.:2281
Median :2666
Mean :2825
3rd Qu.:3212
Max. :4794
fit3 <- vglm(y ~ 1, truncpareto(2000, 4794), data = pdataH, trace = TRUE)
Error in eval(expr, envir, enclos) :
the value of argument 'lower' is too high (requires '0 < lower < min(y)')
This is odd as the usage format is - truncpareto(lower, upper), and varying 2000 to 1900 and 2100 makes no difference. Neither do smaller or larger variations. From the summary I think that my lowest input is 2000, which I am taking as min(y). I have also played with the upper limit. pdataH has 2117 observations in it.
Is this a data format thing? i.e. of pdataH (a tried a few things, but to no avail)
Umm, it doesn't seem to have a column called "y"?
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com
--
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com