[R] truncpareto() - doesn't like my data and odd error message

[peter dalgaard]

Look closer....

-pd


> On 10 Mar 2016, at 18:41 , John Hillier <J.Hillier at lboro.ac.uk> wrote:
> 
> Thank you Peter,
> 
> Yes, it seems to do the same even if I simultaneously make that change.  Output below.
> 
>> pdataH <- data.frame(y = H_to_fit$Height)
>> summary(pdataH)
>       y       
> Min.   :2000  
> 1st Qu.:2281  
> Median :2666  
> Mean   :2825  
> 3rd Qu.:3212  
> Max.   :4794  
>> fit3 <- vglm(y ~ 1, truncpareto(1999, 4794), data = pdataH, trace = TRUE)
> Error in eval(expr, envir, enclos) : 
>  the value of argument 'upper' is too low (requires 'max(y) < upper')
> 
> -------------------------
> Dr John Hillier
> Senior Lecturer - Physical Geography
> Loughborough University
> 01509 223727
> 
> ________________________________________
> From: peter dalgaard <pdalgd at gmail.com>
> Sent: 10 March 2016 09:36
> To: John Hillier
> Cc: r-help at r-project.org
> Subject: Re: [R] truncpareto() - doesn't like my data and odd error message
> 
> Also if you simultaneously change the 2000 to say 1999?
> 
> -p
> 
> On 10 Mar 2016, at 09:22 , John Hillier <J.Hillier at lboro.ac.uk> wrote:
> 
>> Thank you Peter,
>> 
>> I believe this might be the way the error message is hard coded (i.e. it's always y to describe the input).  Anyway, I changed the first line to
>>> pdataH <- data.frame(y = H_to_fit$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
> 

-- 
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