Contents
Which is the best predictor of temporal trends?
It turns out that including time (centered around 1950), month (as a factor), and PDO (Pacific Decadal Oscillation) trend data create the ‘best’ model (i.e., the one with the lowest AIC and in which each predictor improves the model significantly).
Why does the temp data oscillate every year?
The temp data clearly oscillates annually due to monthly/seasonal trends. The temp data also appears to have approx 20-30-yr cycles when graphically viewing annual trends (by plotting annual avg temps across year): Models: I tried a number of gls models and selected models that had lower AICs to move forward with.
How often does the temp data have a cycle?
The temp data also appears to have approx 20-30-yr cycles when graphically viewing annual trends (by plotting annual avg temps across year): Models: I tried a number of gls models and selected models that had lower AICs to move forward with. I also checked the significance of adding predictors based on ANOVA.
How to forecast using time series regression models?
The basic concept is that we forecast the time series of interest y y assuming that it has a linear relationship with other time series x x. For example, we might wish to forecast monthly sales y y using total advertising spend x x as a predictor.
How to interpret the intercept of a regression table?
Interpreting the Intercept The intercept term in a regression table tells us the average expected value for the response variable when all of the predictor variables are equal to zero. In this example, the regression coefficient for the intercept is equal to 48.56 .
What are the predictor variables in a regression model?
The predictor variables x x are sometimes also called the regressors, independent or explanatory variables. In this book we will always refer to them as the “forecast” variable and “predictor” variables.