# plot.tgp

##### Plotting for Treed Gaussian Process Models

A generic function for plotting of `"tgp"`

-class objects.
1-d posterior mean and error plots, 2-d posterior mean and
error image and perspective plots, and 3+-dimensional mean and error
image and perspective plots are supported via projection
and slicing.

##### Usage

```
# S3 method for tgp
plot(x, pparts = TRUE, proj = NULL, slice = NULL,
map = NULL, as = NULL, center = "mean", layout = "both",
main = NULL, xlab = NULL, ylab = NULL, zlab = NULL, pc = "pc",
gridlen = c(40,40), span = 0.1, pXX = TRUE,
legendloc = "topright", maineff = TRUE, mrlayout="both",
rankmax = 20, ...)
```

##### Arguments

- x
`"tgp"`

-class object that is the output of one of the`b*`

functions:`blm`

,`btlm`

`bgp`

,`bgpllm`

,`btgp`

, or`btgpllm`

- pparts
If

`TRUE`

, partition-regions are plotted (default), otherwise they are not- proj
1-or-2-Vector describing the dimensions to be shown in a projection. The argument is ignored for 1-d data, i.e., if

`x$d == 1`

. For 2-d data, no projection needs be specified--- the default argument (`proj = NULL`

) will result in a 2-d perspective or image plot. 1-d projections of 2-d or higher data are are supported, e.g.,`proj = c(2)`

would show the second variable projection. For 3-d data or higher,`proj=NULL`

defaults to`proj = c(1,2)`

which plots a 2-d projection for the first two variables. Slices have priority over the projections--- see next argument (`slice`

)--- when non-null arguments are provided for both.- slice
`list`

object with`x`

and`z`

fields, which are vectors of equal length describing the slice to be plotted, i.e., which z-values of the`x$d - 2`

inputs`x$X`

and`x$XX`

should be fixed to in order to obtain a 2-d visualization. For example, for 4-d data,`slice = list(x=(2,4), z=c(0.2, 1.5)`

will result in a 2-d plot of the first and third dimensions which have the second and fourth slice fixed at 0.5 and 1.5. The default is`NULL`

, yielding to the`proj`

argument. Argument is ignored for 1-d data, i.e., if`x$d == 1`

- map
Optional 2-d map (longitude and latitude) from maps to be shown on top of image plots

- center
Default

`center = "mean"`

causes the posterior predictive mean to be plotted as the centering statistic. Otherwise the median can be used with`center = "med"`

, or the kriging mean with`center = "km"`

- as
Optional string indicator for plotting of adaptive sampling statistics: specifying

`as = "alm"`

for ALM,`as = "s2"`

for predictive variance,`as = "ks2"`

for expected kriging variance,`as = "alc"`

for ALC, and`as = "improv"`

for expected improvement (about the minimum, see the`rankmax`

argument below). The default`as = NULL`

plots error-bars (1d-plots) or error magnitudes (2d-plots), which is essentially the same as`as = "alm"`

- layout
Specify whether to plot the mean predictive surface (

`layout = "surf"`

), the error or adaptive sampling statistics (`layout = "as"`

), or default (`layout = "both"`

) which shows both. If`layout = "sens"`

, plot the results of a sensitivity analysis (see`sens`

) in a format determined by the argument`maineff`

below.- main
Optional

`character`

string to add to the main title of the plot- xlab
Optional

`character`

string to add to the x label of the plots- ylab
Optional

`character`

string to add to the y label of the plots- zlab
Optional

`character`

string to add to the z label of the plots; ignored unless`pc = "p"`

- pc
Selects perspective-posterior mean and image-error plots (

`pc = "pc"`

, the default) or a double--image plot (`pc = "c"`

)- gridlen
Number of regular grid points for 2-d slices and projections in x and y. The default of

`gridlen = c(40,40)`

causes a`40 * 40`

grid of`X`

,`Y`

, and`Z`

values to be computed. Ignored for 1-d plots and projections- span
Span for

`loess`

kernel. The tgp package default (`span = 0.1`

) is set lower than the`loess`

default. Smaller spans can lead to warnings from`loess`

when the data or predictive locations are sparse and ugly plots may result. In this case, try increasing the span- pXX
scalar logical indicating if

`XX`

locations should be plotted- legendloc
Location of the

`legend`

included in the plots of sensitivity analyses produced with`layout = "sens"`

, or 1-d plots of multi-resolution models (with`corr = "mrexpsep"`

) and option`mrlayout = "both"`

; otherwise the argument is ignored- maineff
Format for the plots of sensitivity analyses produced with

`layout = "sens"`

; otherwise the argument is ignored. If`maineff=TRUE`

main effect plots are produced alongside boxplots for posterior samples of the sensitivity indices, and if`FALSE`

only the boxplots are produced. Alternatively,`maineff`

can be a matrix containing input dimensions in the configuration that the corresponding main effects are to be plotted; that is,`mfrow=dim(maineff)`

. In this case, a 90 percent interval is plotted with each main effect and the sensitivity index boxplots are not plotted.- mrlayout
The plot layout for double resolution tgp objects with

`params$corr == "mrexpsep"`

. For the default`mrlayout="both"`

, the coarse and fine fidelity are plotted together, either on the same plot for 1D inputs or through side-by-side image plots of the predicted`center`

with axis determined by`proj`

for inputs of greater dimension. Note that many of the standard arguments -- such as`slice`

,`pc`

, and`map`

-- are either non-applicable or unsupported for`mrlayout="both"`

. If`mrlayout="coarse"`

or`mrlayout="fine"`

, prediction for the respective fidelity is plotted as usual and all of the standard options apply.- rankmax
When

`as = "improv"`

is provided, the posterior expected improvements are plotted according the the first column of the`improv`

field of the`"tgp"`

-class object. Text is added to the plot near the`XX`

positions of the first`1:rankmax`

predictive locations with the highest ranks in the second column of the`improv`

field.- …
Extra arguments to 1-d (

`plot`

) and 2-d plotting functions`persp`

and`image`

##### Value

The only output of this function is beautiful plots

##### Note

This plotting function is provided with the intention that it
will be used as an aid in the visualization of `"tgp"`

-class
objects. Users are encouraged to use the source code for
this function in order to develop custom plotting functions.

1-d projections for 3-d or higher data are also available
by specifying a 1-d projection argument (e.g. `proj=c(1)`

for projecting onto the first input variable).

For examples, see `vignette("tgp")`

and the
help files of those functions in "See Also", below

##### References

##### See Also

`plot`

, `bgpllm`

, `btlm`

,
`blm`

, `bgp`

, `btgpllm`

,
`predict.tgp`

,
`tgp.trees`

, `mapT`

, `loess`

, `sens`

*Documentation reproduced from package tgp, version 2.4-17, License: LGPL*