forceScheme {mp} | R Documentation |
Force Scheme Projection
Description
Creates a 2D representation of the data based on a dissimilarity matrix. A few modifications have been made in relation to the method described in the literature: shuffled indices are used to minimize the order dependency factor, only a fraction of delta is used for better stability and a tolerance factor was introduced as a second stop criterion.
Usage
forceScheme(D, Y = NULL, max.iter = 50, tol = 0, fraction = 8,
eps = 1e-05)
Arguments
D |
A dissimilarity structure such as that returned by dist or a full symmetric matrix containing the dissimilarities. |
Y |
Initial 2D configuration. A random configuration will be used when omitted. |
max.iter |
Maximum number of iterations that the algorithm will run. |
tol |
The tolerance for the accumulated error between iterations. If set to 0, the algorithm will run max.iter times. |
fraction |
Controls the point movement. Larger values means less freedom to move. |
eps |
Minimum distance between two points. |
Value
The 2D representation of the data.
References
Eduardo Tejada, Rosane Minghim, Luis Gustavo Nonato: On improved projection techniques to support visual exploration of multi-dimensional data sets. Information Visualization 2(4): 218-231 (2003)
See Also
dist
(stats) and dist
(proxy) for d computation
Examples
# Eurodist example
emb <- forceScheme(eurodist)
plot(emb, type = "n", xlab ="", ylab ="", asp=1, axes=FALSE, main="")
text(emb, labels(eurodist), cex = 0.6)
# Iris example
emb <- forceScheme(dist(iris[,1:4]))
plot(emb, col=iris$Species)