11.49 Scatter Plot Colour Alternative
%>% ds sample_n(1000) %>% ggplot(aes(x=min_temp, y=max_temp, colour=rain_tomorrow)) + geom_point() + scale_colour_brewer(palette="Set2") + labs(x = vnames["min_temp"], y = vnames["max_temp"], colour = vnames["rain_tomorrow"])
The simplest plot is a scatter plot which displays points scattered over a plot. If the dataset is large the resulting plot will be rather dense. For illustrative purposes a random subset of just 1,000 observations is used. A linear relationship between the two variables can be seen.
The random sample of 1,000 rows is generated using
dplyr::sample_n() and is then piped through to
ggplot2::ggplot(). The function argument identifies the aesthetics
of the plot so that x= associates the variable
min_temp with the x-axis and y= associates the
max_temp with the y-axis.
In addition the colour= option provides a mechanism to
distinguish between days where the observation
Yex and where it is No. A colour palette can be chosen using
A graphical layer is added to the plot consisting of \((x,y)\) points coloured appropriately. The function ggplot2::geom_point() achieves this.
The original variable names stored as
vnames are used to
label the plot using ggplot2::labs(). The original names will
make more sens to the reader than our chosen normalised names.
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