Data Science Desktop Survival Guide by Graham Williams
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ML Setup

20210102 Packages used in this chapter include ROCR, ggplot2, rpart, and rattle.

Packages are loaded into the currently running R session from your local library directories on disk. Missing packages can be installed using utils::install.packages() within R. On Ubuntu, for example, R packages can be installed using wajig install r-cran-<pkgname>.

# Load required packages from local library into the R session.

library(ROCR)         # Use prediction() for evaluation.
library(ggplot2)      # Display evaluations.
library(rattle)       # Dataset: weather.
library(rpart)        # ML: decision tree rpart().
library(scales)       # Support: commas(), percent().

The rattle::weatherAUS dataset is loaded into the template variable ds and further template variables are setup as introduced in Williams (2017). See Chapter 7 for details.

dsname <- "weatherAUS"
ds     <- get(dsname)

nobs   <- nrow(ds)

vnames <- names(ds)
ds    %<>% clean_names(numerals="right")
names(vnames) <- names(ds)

vars   <- names(ds)
target <- "rain_tomorrow"
vars   <- c(target, vars) %>% unique() %>% rev()

It is always useful to remind ourselves of the dataset with a random sample:

ds  %>% sample_frac() %>% select(date, location, sample(3:length(vars), 5))

## # A tibble: 176,747 x 7
##    date       location   wind_dir_9am rainfall min_temp wind_speed_3pm t...
##    <date>     <chr>      <ord>           <dbl>    <dbl>          <dbl>  ...
##  1 2018-01-29 NorahHead  NNE               0.2     21.7             17  ...
##  2 2017-11-22 Dartmoor   NNE               0       14.9             11  ...
##  3 2020-02-16 Melbourne~ SW                3.4     15.2             11  ...
##  4 2015-11-03 Penrith    SW                0.2     17.7             11  ...
##  5 2019-07-26 Canberra   NNE               0       -1.8              9  ...
##  6 2010-09-26 Watsonia   NE                0        6.9             19  ...
##  7 2010-09-21 BadgerysC~ NNW               0.2      6.3             24  ...
##  8 2010-08-24 Brisbane   W                10.2     14               20  ...
....