"mortality" is the daily number of deaths.
many thanks again for your patience and for your help.
agostino
Il giorno 02/lug/2014, alle ore 19:59, David Winsemius ha scritto:
>
> On Jul 2, 2014, at 8:37 AM, Agostino Di Ciaula wrote:
>
>> My aim was to perform a a generalized additive model with penalized splines to analyze the relationship between daily mortality and PM10 levels, and to control for the non-linear confounding effects of weather (temperature = “Tmax”; humidity = “umidità”).
>>
>> this is my complete analysis:
>>> x.gam <- gam(mortality ~ s(PM10) + (Tmax) + (umidità), data = sab, family = quasipoisson)
>>> summary (x.gam)
>>
>> Family: quasipoisson
>> Link function: log
>>
>> Formula:
>> mortality ~ s(PM10) + (Tmax) + (umidità)
>>
>> Parametric coefficients:
>> Estimate Std. Error t value Pr(>|t|)
>> (Intercept) 1.50456 0.83802 1.795 0.0784 .
>> Tmax 0.02060 0.01760 1.170 0.2472
>> umidità 0.01256 0.00826 1.520 0.1345
>> ---
>> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>>
>> Approximate significance of smooth terms:
>> edf Ref.df F p-value
>> s(PM10) 3.067 3.857 4.862 0.00235 **
>> ---
>> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>>
>> R-sq.(adj) = 0.269 Deviance explained = 34.2%
>> GCV score = 6.6782 Scale est. = 5.9797 n = 58
>>
>> Can I assume that the y axis of the plot (which is labeled "sPM10,3.07)
>> plot(x.gam, page =1)
>> is the log relative risk ?
>
> You have repeatedly ignored my suggestions that you describe the data. Without knowing what was measured or counted in the column of data named "mortality", I doubt that anyone (and certainly not I) can offer reassurances or advice about what to assume.
>
> --
> David.
>>
>> thanks again
>> agostino
>>
>> Il giorno 02/lug/2014, alle ore 16:41, David Winsemius ha scritto:
>>
>>>
>>> On Jul 2, 2014, at 1:25 AM, agostinodiciaula@tiscali.it wrote:
>>>
>>>> Sorry for my unclear request and description
>>>> I performed:
>>>>
>>>> x.gam <- gam(mortality ~ s(PM10) + (Tmax) + (umidity), data = data, family = quasipoisson)
>>>> plot(x.gam, page =1)
>>>>
>>>> the plot showed on the left axis "sPM10,3.07".
>>>> How can I have "Log relative risk" ?
>>>
>>> You just want to change the axis label? Then add this to the plot call:
>>>
>>> ylab="Log Relative Hazard"
>>>
>>> Again, you have not told us anything about the data, so we remain unable to say whether the results corresponds to that label change, but with a quasipoisson link one might expect a logged estimate of .
>>>
>>> --
>>> David
>>>
>>>> thanks again for your kind help
>>>> agostino
>>>>
>>>> Il 02.07.2014 08:42 David Winsemius ha scritto:
>>>>
>>>>> On Jul 1, 2014, at 11:33 PM, agostinodiciaula@tiscali.itwrote:
>>>>>> Dear David, many thanks for your reply. The aim was to evaluate the relationship between daily mortality (variable "mortality") and mean daily values of PM10 levels (variable "PM10") in a specific geographic area, considering the effect of meteorological confounders (temperature, umidity). I used the following model (mgcv package): gam(mortality ~ (PM10) + (Tmax) + (umidity), data = data, family = quasipoisson) the question is: how can I obtain a plot of log-relative risk of daily mortality vs. PM10 levels? regards
>>>>> Still rather unclear what the problem is. I see no error message in your question. Are you asking how to assign a model to a name and then call the plot method?
>>>>>
>>>>> mdlAgostino
>>>>> Il 02.07.2014 01:50 David Winsemius ha scritto:
>>>>>
>>>>>> On Jul 1, 2014, at 12:02 AM, adc wrote:
>>>>>>> I performed the following GAM by the MGCV package:
>>>>>> I think it's actually spelled in all lower case.
>>>>>>> gam(mortality ~ (PM10) + (Tmax) + (umidity), data = data, family = quasipoisson) How can I obtain a plot of Log-relative risk of mortality vs. PM10 ? thanks
>>>>>> Shouldn't we need to know more details about the experimental setup to answer that question? And what sort of comparisons you are requesting? And about what parts of ?mgcv::plot.gam you need further explanations to answer the question?
>>>>>>> agostino
>>>>>> snipped
>>>>>>> --
>>>>>> snipped
>>>>>>> Sent from the R help mailing list archive at Nabble.com. [[alternative HTML version deleted]]
>>>>>> snipped
>>>>>>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
>
> snipped
>
>
>
> David Winsemius
> Alameda, CA, USA
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