scatter {qacBase}

Scatterplot

Description

Create a scatter plot between two quantitative variables.

Usage

scatter(
  data,
  x,
  y,
  outlier = 3,
  alpha = 1,
  digits = 3,
  title,
  margin = "none",
  stats = TRUE,
  point_color = "deepskyblue2",
  outlier_color = "violetred1",
  line_color = "grey30",
  margin_color = "deepskyblue2"
)

Arguments

data

data frame

x

quantitative predictor variable

y

quantitative response variable

outlier

number. Observations with studentized residuals larger than this value are flagged. If set to 0, observations are not flagged.

alpha

Transparency of data points. A numeric value between 0 (completely transparent) and 1 (completely opaque).

digits

Number of significant digits in displayed statistics.

title

Optional title.

margin

Marginal plots. If specified, parameter can be histogram, boxplot, violin, or density. Will add these features to the top and right margin of the graph.

stats

logical. If TRUE, the slope, correlation, and correlation squared (expressed as a percentage) for the regression line are printed on the subtitle line.

point_color

Color used for points.

outlier_color

Color used to identify outliers (see the outlier parameter.

line_color

Color for regression line.

margin_color

Fill color for margin boxplots, density plots, or histograms.

Details

The scatter function generates a scatterplot between two quantitative variables, along with a line of best fit and a 95% confidence interval. By default, regression statistics (b, r, r2, p) are printed and outliers (observations with studentized residuals > 3) are flagged. Optionally, variable distributions (histograms, boxplots, violin plots, density plots) can be added to the plot margins.

Value

a ggplot2 graph

Note

Variable names do not have to be quoted.

Examples

scatter(cars74, hp, mpg)
scatter(cars74, wt, hp)
p <- scatter(ggplot2::mpg, displ, hwy,
        margin="histogram",
        title="Engine Displacement vs. Highway Mileage")
plot(p)