[R] Trend value from smoothing spline trend fit

[Dileepkumar R]

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]]