parcoordMiss {VIM} | R Documentation |
Parallel coordinate plot with adjustments for missing/imputed values. Missing values in the plotted variables may be represented by a point above the corresponding coordinate axis to prevent disconnected lines. In addition, observations with missing/imputed values in selected variables may be highlighted.
parcoordMiss(x, delimiter = NULL, highlight = NULL, selection = c("any","all"), plotvars = NULL, plotNA = TRUE, col = c("skyblue","red","skyblue4","red4","orange","orange4"), alpha = NULL, lty = par("lty"), xlim = NULL, ylim = NULL, main = NULL, sub = NULL, xlab = NULL, ylab = NULL, labels = TRUE, xpd = NULL, interactive = TRUE, ...) TKRparcoordMiss(x, delimiter = NULL, highlight = NULL, selection = c("any","all"), plotvars = NULL, plotNA = TRUE, col = c("skyblue","red","skyblue4","red4","orange","orange4"), alpha = NULL, ..., hscale = NULL, vscale = 1, TKRpar = list())
x |
a matrix or |
delimiter |
a character-vector to distinguish between variables
and imputation-indices for imputed variables (therefore, |
highlight |
a vector giving the variables to be used for highlighting.
If |
selection |
the selection method for highlighting missing/imputed values in
multiple highlight variables. Possible values are |
plotvars |
a vector giving the variables to be plotted. If |
col |
if |
plotNA |
a logical indicating whether missing values in the plot variables should be represented by a point above the corresponding coordinate axis to prevent disconnected lines. |
alpha |
a numeric value between 0 and 1 giving the level of transparency
of the colors, or |
lty |
if |
xlim, ylim |
axis limits. |
main, sub |
main and sub title. |
xlab, ylab |
axis labels. |
labels |
either a logical indicating whether labels should be plotted below each coordinate axis, or a character vector giving the labels. |
xpd |
a logical indicating whether the lines should be allowed to go
outside the plot region. If |
interactive |
a logical indicating whether interactive features should be enabled (see ‘Details’). |
... |
for |
hscale |
horizontal scale factor for plot to be embedded in a Tcl/Tk window (see ‘Details’). The default value depends on the number of variables. |
vscale |
vertical scale factor for the plot to be embedded in a Tcl/Tk window (see ‘Details’). |
TKRpar |
a list of graphical parameters to be set for the plot to be
embedded in a Tcl/Tk window (see ‘Details’ and
|
In parallel coordinate plots, the variables are represented by parallel
axes. Each observation of the scaled data is shown as a line. Observations
with missing/imputed values in selected variables may thereby be highlighted.
However, plotting variables with missing values results in disconnected
lines, making it impossible to trace the respective observations across
the graph. As a remedy, missing values may be represented by a point above
the corresponding coordinate axis, which is separated from the main plot by a
small gap and a horizontal line, as determined by plotNA
. Connected
lines can then be drawn for all observations. Nevertheless, a caveat of this
display is that it may draw attention away from the main relationships
between the variables.
If interactive
is TRUE
, it is possible switch between this
display and the standard display without the separate level for missing
values by clicking in the top margin of the plot. In addition, the variables
to be used for highlighting can be selected interactively. Observations with
missing/imputed values in any or in all of the selected variables are highlighted (as
determined by selection
). A variable can be added to the selection by
clicking on a coordinate axis. If a variable is already selected, clicking
on its coordinate axis removes it from the selection. Clicking anywhere
outside the plot region (except the top margin, if missing/imputed values exist)
quits the interactive session.
TKRparcoordMiss
behaves like parcoordMiss
, but uses
tkrplot
to embed the plot in a Tcl/Tk window.
This is useful if the number of variables is large, because scrollbars allow
to move from one part of the plot to another.
Some of the argument names and positions have changed with versions 1.3 and
1.4 due to extended functionality and for more consistency with other plot
functions in VIM
. For back compatibility, the arguments
colcomb
and xaxlabels
can still be supplied to ...
and are handled correctly. Nevertheless, they are deprecated and no longer
documented. Use highlight
and labels
instead.
Andreas Alfons, Matthias Templ, modifications by Bernd Prantner
Wegman, E. J. (1990) Hyperdimensional data analysis using parallel coordinates. Journal of the American Statistical Association 85 (411), 664–675.
M. Templ, A. Alfons, P. Filzmoser (2012) Exploring incomplete data using visualization tools. Journal of Advances in Data Analysis and Classification, Online first. DOI: 10.1007/s11634-011-0102-y.
data(chorizonDL, package = "VIM") ## for missing values parcoordMiss(chorizonDL[,c(15,101:110)], plotvars=2:11, interactive = FALSE) legend("top", col = c("skyblue", "red"), lwd = c(1,1), legend = c("observed in Bi", "missing in Bi")) ## for imputed values parcoordMiss(kNN(chorizonDL[,c(15,101:110)]), delimiter = "_imp" , plotvars=2:11, interactive = FALSE) legend("top", col = c("skyblue", "orange"), lwd = c(1,1), legend = c("observed in Bi", "imputed in Bi"))