| plot.fechner {fechner} | R Documentation |
Plot Method for Objects of Class fechner
Description
S3 method to plot objects of the class fechner.
Usage
## S3 method for class 'fechner'
plot(x, level = 2, ...)
Arguments
x |
a required object of class |
level |
an optional numeric, integer-valued and greater than or
equal to |
... |
further arguments to be passed to or from other methods. They are ignored in this function. |
Details
The plot method graphs the results obtained from Fechnerian
scaling analyses. It produces a scatterplot of the overall
Fechnerian distance G versus the S-index, with rugs
added to the axes and jittered (amount = 0.01 of noise) to
accommodate ties in the S-index and G values. The
diagonal line y = x is for visual inspection of the deviations
of the two types of values.
The level of comparison refers to the minimum number of links
in geodesic loops. That is, choosing level n means that
comparison involves only those S-index and G values that
have geodesic loops containing not less than n links.
If there are no (off-diagonal) pairs of stimuli with geodesic loops
containing at least level links (in this case a plot is not
possible), plot.fechner stops with an error message.
Value
If the arguments x and level are of required types,
and if there are (off-diagonal) pairs of stimuli with geodesic loops
containing at least level links, plot.fechner produces
a plot, and invisibly returns NULL.
Author(s)
Thomas Kiefer, Ali Uenlue. Based on original MATLAB source by Ehtibar N. Dzhafarov.
References
Dzhafarov, E. N. and Colonius, H. (2006) Reconstructing distances among objects from their discriminability. Psychometrika, 71, 365–386.
Dzhafarov, E. N. and Colonius, H. (2007) Dissimilarity cumulation theory and subjective metrics. Journal of Mathematical Psychology, 51, 290–304.
Uenlue, A. and Kiefer, T. and Dzhafarov, E. N. (2009) Fechnerian scaling in R: The package fechner. Journal of Statistical Software, 31(6), 1–24. URL http://www.jstatsoft.org/v31/i06/.
See Also
print.fechner, the S3 method for printing objects of
the class fechner; summary.fechner, the S3
method for summarizing objects of the class fechner, which
creates objects of the class summary.fechner;
print.summary.fechner, the S3 method for printing
objects of the class summary.fechner; fechner,
the main function for Fechnerian scaling, which creates objects of
the class fechner. See also fechner-package
for general information about this package.
Examples
## Fechnerian scaling of dataset \link{wish}
f.scal.wish <- fechner(wish)
## results are plotted for comparison levels 2 and 5
plot(f.scal.wish)
plot(f.scal.wish, level = 5)