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 > <dwinsem...@comcast.net> ha scritto: > >> >> On Jul 2, 2014, at 1:25 AM, agostinodicia...@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 <something>. >> >> -- >> 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 ______________________________________________ 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.
