Dear Bert Gunter and Mathew Guilfoyle, Thanks for the reply.
I also agree with you. But that is the actual slope of the straight line connecting from the first estimated value to last estimated value ( like dy/dx slope). I tried in that way also, but I couldn't replicate the results as given in that Box 2.2, Table 1 and Figure 1. I can replicate the line plot as in Box 2.2, Figure 1 (a) (to verify my input data is the same as in Figure 1 (a)). You can see my plot here: https://drive.google.com/file/d/14WDFFW5J69WvxnhbfdcOZKvGRk6HUWVn/view?usp=sharing I have attached my code and data (as NetCDF file) along with this mail. input Data (only 32Kb) : https://drive.google.com/file/d/1Wt5sjVhWmjhRWOfdc6elUzwOvifRk-OI/view?usp=sharing code: https://drive.google.com/file/d/1r5mg1vcNmDCIf19jnMUAFEiLNOLKQiKq/view?usp=sharing output figure: https://drive.google.com/file/d/1bEXWCB-H5doVKXO8i_FLO7KZMW3qc9Cw/view?usp=sharing Sincerely, Dileepkumar R On Tue, Aug 11, 2020 at 11:41 PM Mathew Guilfoyle <mrguilfo...@gmail.com> wrote: > Looking at the report (specifically the legend for the table) I think all > they have done is take the difference between fitted temperatures (given by > linear regression or the GAM) at the start and end of each period (e.g. in > 1901 and 2012), and then calculate the average change per year. > > In a way it ‘linearises’ the spline trend but I don’t think it’s really > valid. It just highlights how poorly a (simple) linear regression can fit > a very non-linear trend. > > > On 11 Aug 2020, at 13:21, Dileepkumar R <dileepkunj...@gmail.com> wrote: > > > > Dear All, > > > > I am trying to estimate the non -linear trend value from smooth spline > > trend fit (using the generalized additive model (GAM)). > > > > I want to estimate the trend value from a temperature dataset (spatial > > averaged annual meantime from 1906 to 2005) as given in the Box 2.2, > Table > > 1 in the attached Google doc pdf. (That pages are from IPCC Assessment > > Report 5 chapter 2 > > < > https://www.ipcc.ch/site/assets/uploads/2017/09/WG1AR5_Chapter02_FINAL.pdf > >, > > page number 21-22 ) > > > > I do not understand how they estimate the single value trend with 95% > > confidence interval from a time-series data as given in the Box 2.2, > Figure > > 1. Is there any easy way to extract the trend value using mgcv library > of > > R.? > > > > Google Doc Link: > > > https://drive.google.com/file/d/1z3XLW-154dsZE6GrvQ4rH_fev9lqdsho/view?usp=sharing > > > > Thank you all in advance > > > > Dileepkumar R > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
