```r
x <- rnorm(1000)                   # atomic vectors
y <- x + rnorm(1000, sd=.5)
df <- data.frame(x=x, y=y)         # object of class 'data.frame'
plot(y ~ x, df)                    # generic plot, method plot.formula
```

![plot of chunk unnamed-chunk-1](figure/unnamed-chunk-1.png) 

```r
fit <- lm(y ~x, df)                # object of class 'lm'
methods(class=class(fit))          # introspection
```

```
##  [1] add1.lm*           alias.lm*          anova.lm*         
##  [4] case.names.lm*     confint.lm         cooks.distance.lm*
##  [7] deviance.lm*       dfbeta.lm*         dfbetas.lm*       
## [10] drop1.lm*          dummy.coef.lm      effects.lm*       
## [13] extractAIC.lm*     family.lm*         formula.lm*       
## [16] hatvalues.lm*      influence.lm*      kappa.lm          
## [19] labels.lm*         logLik.lm*         model.frame.lm*   
## [22] model.matrix.lm    nobs.lm*           plot.lm*          
## [25] predict.lm         print.lm*          proj.lm*          
## [28] qr.lm*             residuals.lm       rstandard.lm*     
## [31] rstudent.lm*       simulate.lm*       summary.lm        
## [34] variable.names.lm* vcov.lm*          
## 
##    Non-visible functions are asterisked
```