# termplot

##### Plot Regression Terms

Plots regression terms against their predictors, optionally with standard errors and partial residuals added.

- Keywords
- hplot, regression

##### Usage

```
termplot(model, data = NULL, envir = environment(formula(model)),
partial.resid = FALSE, rug = FALSE,
terms = NULL, se = FALSE,
xlabs = NULL, ylabs = NULL, main = NULL,
col.term = 2, lwd.term = 1.5,
col.se = "orange", lty.se = 2, lwd.se = 1,
col.res = "gray", cex = 1, pch = par("pch"),
col.smth = "darkred", lty.smth = 2, span.smth = 2/3,
ask = dev.interactive() && nb.fig < n.tms,
use.factor.levels = TRUE, smooth = NULL, ylim = "common",
plot = TRUE, transform.x = FALSE, …)
```

##### Arguments

- model
fitted model object

- data
data frame in which variables in

`model`

can be found- envir
environment in which variables in

`model`

can be found- partial.resid
logical; should partial residuals be plotted?

- rug
add rugplots (jittered 1-d histograms) to the axes?

- terms
which terms to plot (default

`NULL`

means all terms); a vector passed to`predict(.., type = "terms", terms = *)`

.- se
plot pointwise standard errors?

- xlabs
vector of labels for the x axes

- ylabs
vector of labels for the y axes

- main
logical, or vector of main titles; if

`TRUE`

, the model's call is taken as main title,`NULL`

or`FALSE`

mean no titles.- col.term, lwd.term
color and line width for the ‘term curve’, see

`lines`

.- col.se, lty.se, lwd.se
color, line type and line width for the ‘twice-standard-error curve’ when

`se = TRUE`

.- col.res, cex, pch
color, plotting character expansion and type for partial residuals, when

`partial.resid = TRUE`

, see`points`

.- ask
logical; if

`TRUE`

, the user is*ask*ed before each plot, see`par(ask=.)`

.- use.factor.levels
Should x-axis ticks use factor levels or numbers for factor terms?

- smooth
`NULL`

or a function with the same arguments as`panel.smooth`

to draw a smooth through the partial residuals for non-factor terms- lty.smth, col.smth, span.smth
Passed to

`smooth`

- ylim
an optional range for the y axis, or

`"common"`

when a range sufficient for all the plot will be computed, or`"free"`

when limits are computed for each plot.- plot
if set to

`FALSE`

plots are not produced: instead a list is returned containing the data that would have been plotted.- transform.x
logical vector; if an element (recycled as necessary) is

`TRUE`

, partial residuals for the corresponding term are plotted against transformed values. The model response is then a straight line, allowing a ready comparison against the data or against the curve obtained from`smooth-panel.smooth`

.- …
other graphical parameters.

##### Details

The `model`

object must have a `predict`

method that accepts
`type = "terms"`

, e.g., `glm`

in the stats package,
`coxph`

and `survreg`

in
the survival package.

For the `partial.resid = TRUE`

option `model`

must have a
`residuals`

method that accepts `type = "partial"`

,
which `lm`

and `glm`

do.

The `data`

argument should rarely be needed, but in some cases
`termplot`

may be unable to reconstruct the original data
frame. Using `na.action=na.exclude`

makes these problems less likely.

Nothing sensible happens for interaction terms, and they may cause errors.

The `plot = FALSE`

option is useful when some special action is needed,
e.g.to overlay the results of two different models or to plot
confidence bands.

##### Value

For `plot = FALSE`

, a list with one element for each plot which
would have been produced. Each element of the list is a data frame
with variables `x`

, `y`

, and optionally the pointwise
standard errors `se`

. For continuous predictors `x`

will
contain the ordered unique values and for a factor it will be a factor
containing one instance of each level. The list has attribute
`"constant"`

copied from the predicted terms object.

Otherwise, the number of terms, invisibly.

##### See Also

For (generalized) linear models, `plot.lm`

and
`predict.glm`

.

##### Examples

`library(stats)`

```
# NOT RUN {
require(graphics)
had.splines <- "package:splines" %in% search()
if(!had.splines) rs <- require(splines)
x <- 1:100
z <- factor(rep(LETTERS[1:4], 25))
y <- rnorm(100, sin(x/10)+as.numeric(z))
model <- glm(y ~ ns(x, 6) + z)
par(mfrow = c(2,2)) ## 2 x 2 plots for same model :
termplot(model, main = paste("termplot( ", deparse(model$call)," ...)"))
termplot(model, rug = TRUE)
termplot(model, partial.resid = TRUE, se = TRUE, main = TRUE)
termplot(model, partial.resid = TRUE, smooth = panel.smooth, span.smth = 1/4)
if(!had.splines && rs) detach("package:splines")
# }
# NOT RUN {
## requires recommended package MASS
hills.lm <- lm(log(time) ~ log(climb)+log(dist), data = MASS::hills)
termplot(hills.lm, partial.resid = TRUE, smooth = panel.smooth,
terms = "log(dist)", main = "Original")
termplot(hills.lm, transform.x = TRUE,
partial.resid = TRUE, smooth = panel.smooth,
terms = "log(dist)", main = "Transformed")
# }
```

*Documentation reproduced from package stats, version 3.6.2, License: Part of R 3.6.2*