4 fitres() and fitresdf()

The function fitres() will look similar to those who have used augment() from broom. It creates a matrix of the fitted values, residuals, and residuals as a proportion (percent) based on the actual dependent variable’s values. When the data input is specified, the function produces a dataframe that merges the fitted values and residual variables as columns to said specified dataset. The function fitresdf() acts similarly except that its output is a data frame.

4.1 Without specifying data

model.lm <- lm(data = mtcars, formula = mpg ~ wt + gear)

head(fitres(model.lm, fit_type = 'response'))
##                        fit   residual residual_pct
## Mazda RX4         23.26669 -2.2666926  -0.10793774
## Mazda RX4 Wag     21.86801 -0.8680127  -0.04133394
## Datsun 710        24.91220 -2.1121984  -0.09264028
## Hornet 4 Drive    20.32266  1.0773414   0.05034305
## Hornet Sportabout 19.08853 -0.3885293  -0.02077697
## Valiant           18.97883 -0.8788289  -0.04855408
    # default type value is 'response'.

4.2 With specifying data

model.lm <- lm(data = mtcars, formula = mpg ~ wt + gear)

head(fitres(model    = model.lm, 
            data     = mtcars, 
            fit_type = 'response'))
##                    mpg cyl disp  hp drat    wt  qsec vs am gear carb      fit
## Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4 23.26669
## Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4 21.86801
## Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1 24.91220
## Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1 20.32266
## Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2 19.08853
## Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1 18.97883
##                     residual residual_pct
## Mazda RX4         -2.2666926  -0.10793774
## Mazda RX4 Wag     -0.8680127  -0.04133394
## Datsun 710        -2.1121984  -0.09264028
## Hornet 4 Drive     1.0773414   0.05034305
## Hornet Sportabout -0.3885293  -0.02077697
## Valiant           -0.8788289  -0.04855408