PsychShape {MixedPsy} | R Documentation |
Plot Psychometric Functions given PSE and JND
Description
Plot a psychometric function with known PSE and JND on a new or existing ggplot
object.
Usage
PsychShape(
pse = 0,
jnd = 1,
p = 0.75,
x.range = c(NA, NA),
ps.link = c("probit"),
ps.type = "solid",
ps.size = 1,
ps.color = "black",
addTo = NULL
)
Arguments
pse , jnd |
point of subjective equivalende (PSE) and just noticeable difference (JND) of the desired psychometric function. |
p |
probability value relative to the JND upper limit. Default is 0.75 (value for 50% JND). |
x.range |
vector of length two specifying the range of the psychometric function. |
ps.link |
a link function for the binomial family of error distribution. |
ps.type , ps.size , ps.color |
type, size, and color of the plotted line (see |
addTo |
specifies an existing |
Details
PsychShape()
can be used to visualize the predicted results of a
psychophysical experiment or to plot a fitted psychometric function whose
values of pse and jnd are known. Currently only working with probit and logit
link function.
Value
PsychShape
returns a ggplot
object.
References
Moscatelli, A., Mezzetti, M., & Lacquaniti, F. (2012). Modeling psychophysical data at the population-level: The generalized linear mixed model. Journal of Vision, 12(11):26, 1-17. doi:10.1167/12.11.26
Knoblauch, K., & Maloney, L. T. (2012). Modeling psychophysical data in R (Vol. 32). Springer Science & Business Media.
See Also
glm
for for Generalized Linear Models.
PsychFunction
and PsychDelta
for estimation of PSE and JND from response data.
PsychPlot
for plotting a a psychometric function from a GLM.
Examples
p <- PsychShape(pse = 0, jnd = 6, x.range = c(-40, 40), ps.color = "gray", ps.size = 3)
p1 <- PsychShape(pse = 6, jnd = 6, x.range = c(-40, 40), ps.col = "black", addTo = p)
p2 <- PsychShape(pse = 6, jnd = 6, x.range = c(-40, 40), ps.col = "red", ps.link = "logit",
ps.type = "dashed", addTo = NULL)