fixPlot: Plot Gaze Fixation Data Over a Bitmap

In davebraze/FDBeye: Functions to Ease Work with Eyetracker Data

Plot Gaze Fixation Data Over a Bitmap

Description

Plot gaze fixation data overlayed on a bitmap image. This is a convenience wrapper around ggplot2::ggplot().

Usage

fixPlot(data, bgImage = NULL, bgAlpha = 0.33,
  xyMap = ggplot2::aes_string(x = "xpos", y = "ypos"),
  pointMap = ggplot2::aes_string(size = "dur"), pointAlpha = 0.5,
  mar = c(0, 0, 0, 0), ..., showPlot = TRUE)

Arguments

data	A data.frame containing one fixation per row. Must include at least x and y coordinates. Origin is assumed to be upper left corner.
bgImage	Path to background image. Must be a PNG file. Usually this will correspond to the visual stimulus being viewed by subjects while their eye movements were recorded.
bgAlpha	Alpha level for background layer. Defaults to .33.
xyMap	Aesthetic mapping (ggplot2::aes_string()) for x and y coordinates. Passed to ggplot().
pointMap	Additional aesthetics specific to points. Passed to geom_point().
pointAlpha	Set fixation point transparency. Defaults to .5.
mar	A 4 vector for margin adjustment (x & y scale limits): top, right, bottom, left. Use positive values move margins toward center of plot (trim the display area). Use negative values to expand the display area beyond the bitmap.
...	Additional arguments passed to ggplot2::geom_point().
showPlot	Logical indicating whether to display the plot. Defaults to TRUE.

Details

This is a convenience function for using ggplot() to lay fixation data over a background bitmap. At present, only PNG files are supported for background images. Usually, these will correspond to the visual stimulus viewed by subjects while gaze was recorded. Function returns a ggplot2 object which can be further modified by ggplot2 geoms.

Value

A ggplot2 object.

Author(s)

Dave Braze [e-mail]

Examples

data <- data.frame(x=seq(10, 1270, length.out=10),
              y=seq(10, 1014, length.out=10))
bg <- system.file("extdata/story01.png", package="FDBeye")
fixPlot(data = data,
        bgImage = bg,
        xyMap = ggplot2::aes_string(x='x', y='y'),
        pointMap =ggplot2::aes_string())

data(EToralreading)
D <- EToralreading
D$label <- as.factor(as.integer(D$label))

fixPlot(data=subset(D, subset=(subj=="s0149")&(story=="1")&(label %in% as.character(1:13))),
        bgImage=system.file("extdata/story01.png", package="FDBeye"),
        pointMap=ggplot2::aes_string(color="as.factor(as.integer(label)%%3)"), size=5,
                                     pointAlpha=.5)

davebraze/FDBeye documentation built on April 28, 2022, 1:20 a.m.