plotImp: Importance barplot

In kerntools: Kernel Functions and Tools for Machine Learning Applications

Importance barplot

Description

'plotImp()' displays the barplot of a numeric vector, which is assumed to contain the features importance (from a prediction model) or the contribution of each original variable to a Principal Component (PCA). In the barplot, features/PCs are sorted by decreasing importance.

Usage

plotImp(
  x,
  y = NULL,
  relative = TRUE,
  absolute = TRUE,
  nfeat = NULL,
  names = NULL,
  main = NULL,
  xlim = NULL,
  color = "grey",
  leftmargin = NULL,
  ylegend = NULL,
  leg_pos = "right",
  ...
)

Arguments

x	Numeric vector containing the importances.
y	(optional) Numeric vector containing a different, independent variable to be contrasted with the feature importances. Should have the same length and order than 'x'.
relative	If TRUE, the barplot will display relative importances. (Defaults: TRUE).
absolute	If FALSE, the bars may be positive or negative, which will affect the order of the features Otherwise, the absolute value of 'x' will be taken (Defaults: TRUE).
nfeat	(optional) The number of top (most important) features displayed in the plot.
names	(optional) The names of the features, in the same order than 'x'.
main	(optional) Plot title.
xlim	(optional) A numeric vector. If absent, the minimum and maximum value of ‘x' will be used to establish the axis’ range.
color	Color(s) chosen for the bars. A single value or a vector. (Defaults: "grey").
leftmargin	(optional) Left margin space for the plot.
ylegend	(optional) It allows to add a text explaining what is 'y' (only if 'y' is not NULL).
leg_pos	If 'ylegend' is TRUE, the position of the legend. (Defaults: "right").
...	(optional) Additional arguments (such as 'axes', 'asp',...) and graphical parameters (such as 'par'). See '?graphics::barplot()'.

Value

A list containing:

* The vector of importances in decreasing order. When 'nfeat' is not NULL, only the top 'nfeat' are returned.

* The cumulative sum of (absolute) importances.

* A numeric vector giving the coordinates of all the drawn bars' midpoints.

Examples

importances <- rnorm(30)
names_imp <- paste0("Feat",1:length(importances))

plot1 <- plotImp(x=importances,names=names_imp,main="Barplot")
plot2 <- plotImp(x=importances,names=names_imp,relative=FALSE,
main="Barplot",nfeat=10)
plot3 <- plotImp(x=importances,names=names_imp,absolute=FALSE,
main="Barplot",color="coral2")

kerntools documentation built on April 3, 2025, 7:52 p.m.