Biplot
biplot(coefs)
h = biplot(coefs,'Name
',Value
)
biplot(coefs)
creates a biplot of the coefficients
in the matrix coefs
. The biplot is 2D if coefs
has
two columns or 3D if it has three columns. coefs
usually
contains principal component coefficients created with pca
, pcacov
,
or factor loadings estimated with factoran
. The
axes in the biplot represent the principal components or latent factors
(columns of coefs
), and the observed variables
(rows of coefs
) are represented as vectors.
A biplot allows you to visualize the magnitude and sign of each variable's contribution to the first two or three principal components, and how each observation is represented in terms of those components.
biplot
imposes a sign convention, forcing
the element with largest magnitude in each column of coefs
to
be positive. This flips some of the vectors in coefs
to
the opposite direction, but often makes the plot easier to read.
Interpretation of the plot is unaffected, because changing the sign
of a coefficient vector does not change its meaning.
biplot
scales the scores so that they fit
on the plot: It divides each score by the maximum absolute value of
all scores, and multiplies by the maximum coefficient length of coefs
.
Then biplot
changes the sign of score coordinates
according to the sign convention for the coefs
.
h = biplot(coefs,'
specifies
one or more name/value input pairs and returns a column vector of
handles to the graphics objects created by Name
',Value
)biplot
.
The h
contains, in order, handles corresponding
to variables (line handles, followed by marker handles, followed by
text handles), to observations (if present, marker handles followed
by text handles), and to the axis lines.

Plots both 

Labels each vector (variable) with the text in the character
array or cell array 

Uses the text in the character array or cell array 

Default: 

Specifies optional property name/value pairs for all Primitive Line Properties graphics
objects created by 
factoran
 nnmf
 pca
 pcacov
 rotatefactors