mousetrap (version 1.0.0)

mt_plot_riverbed: Plot density of mouse positions across time steps.

Description

mt_plot_riverbed creates a plot showing the relative frequency of x-values per time step.

Usage

mt_plot_riverbed(data, use = "tn_trajectories", y = "xpos",
  y_range = NULL, y_bins = 250, x_label = "Time step",
  y_label = "X coordinate")

Arguments

data

mousetrap data object containing the data to be plotted.

use

character string specifying the set of trajectories to use in the plot. The steps of this set will constitute the x axis. Defaults to 'tn_trajectories', which results in time steps being plotted on the x axis.

y

variable in the mousetrap data object to be plotted on the output's y dimension. Defaults to 'xpos', the cursor's x coordinate.

y_range

numerical vector containing two values that represent the upper and lower ends of the y axis. By default, the range is calculated from the data provided.

y_bins

number of bins to distribute along the y axis (defaults to 250).

x_label

label placed on the output's x axis (defaults to 'Time step').

y_label

label placed on the output's y axis (defaults to 'X coordinate', as appropriate given the default for y).

Details

This plot indicates where the majority of trajectories lie, and the degree to which trajectories deviate from the average trajectory. In most data sets, this plot will result in a horizontal line of high density indicating that participants took a certain amount of time before deviating from their starting point.

See Also

mt_plot for plotting trajectory data.

Examples

# Load ggplot2
library(ggplot2)

# Time-normalize trajectories
mt_example <- mt_time_normalize(mt_example)
  
# Create riverbed plot for all trials
mt_plot_riverbed(mt_example)


# Create separate plots for typical and atypical trials:

# assess range for x-positions across both conditions
xpos_range <- range(mt_example$tn_trajectories[,"xpos",])

# create subsets of trials
mt_example_atypical <- mt_subset(mt_example,Condition=="Atypical")
mt_example_typical <- mt_subset(mt_example,Condition=="Typical")

# create separate riverbed plots
mt_plot_riverbed(mt_example_atypical,
  use="tn_trajectories", y_range=xpos_range)+
  ggtitle("Atypical condition")

mt_plot_riverbed(mt_example_typical,
  use="tn_trajectories", y_range=xpos_range)+
  ggtitle("Typical condition")