`library(FunnelPlotR)`

This brief vignette shows how to go about changing some of the parameters available in the `funnelplotr`

package. Firstly, lets set up some data, the same as the README and other vignette:

```
library(COUNT)
#> Loading required package: msme
#> Loading required package: MASS
#> Loading required package: lattice
#> Loading required package: sandwich
data(medpar)
$provnum<-factor(medpar$provnum)
medpar$los<-as.numeric(medpar$los)
medpar
# Logistic model to predict LOS, LOS is quite overdispersed
<- glm(los ~ hmo + died + age80 + factor(type), family="poisson", data=medpar)
mod
# Get predicted value for ratio
$prds<- predict(mod, type="response")
medpar
# Draw plot, returning just the plot object
funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE) ,
```

```
#> A funnel plot object with 54 points of which 9 are outliers.
#> Plot is adjusted for overdispersion.
```

You can alter themes in the `funnelplotr`

packages by using the theme argument. There are a couple of options included with the package `funnel_clean`

(the default) and `funnel_grey`

, but you can write your own theme using any valid `ggplot2`

theme and pass it to the plot.

```
funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE, theme = funnel_grey() ) ,
```

```
#> A funnel plot object with 54 points of which 9 are outliers.
#> Plot is adjusted for overdispersion.
```

If you are not familiar with themes, you can create a theme with the `theme`

function from `ggplot2`

. I will create a new theme, including the `funnel_grey`

theme, but with some different (exaggerated) elements.

```
library(ggplot2)
<-
new_funnel_theme funnel_grey()+
theme(plot.title = element_text(face="bold", colour="red", size=6), # Change plot title
legend.background = element_rect(fill="brown"), # Alter legend background colour
axis.title.y = element_text(angle=0) #Rotate y axis label
)
funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE, theme = new_funnel_theme) ,
```

```
#> A funnel plot object with 54 points of which 9 are outliers.
#> Plot is adjusted for overdispersion.
```

You can change the colours of the limits. I am aiming to allow better colour theme support in future versions, but at present they are supplied as a vector of four hex colours to the `plot_cols`

argument, in the order 95% Poisson, 99.8% Poisson, 95% OD and 99.8% OD. At present all four values are required, whether you are plotting all four limits or not.

I have deliberately avoided using red and green colours as defaults because it encourages value judgements about ‘good’ v.s. ‘bad’ which may be unreasonable for a given data set. Default colours are: `c("#FF7F0EFF", "#1F77B4FF", "#9467BDFF","#2CA02CFF")`

Here are four other colours instead:

```
funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE, plot_cols= c("#8c8c8c", "#00b159", "#00aedb", "#d11141")) ,
```

```
#> A funnel plot object with 54 points of which 9 are outliers.
#> Plot is adjusted for overdispersion.
```

`funnelplotr`

automatically sets it’s scales from the data you present to it but, on occasions, the scale rules might fall down for a particular dataset, or you may want to fix the plot to a particular scale. You can do this using the `xrange`

and `yrange`

arguments. Each takes a vector of two values, the minimum and the maximum:

```
## Changing labels
funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE, xrange=c(0, 400), yrange=c(0,2))
, #> Warning: Removed 17 rows containing missing values (geom_point).
#> Warning: Removed 17 rows containing missing values (geom_label_repel).
```

```
#> A funnel plot object with 54 points of which 9 are outliers.
#> Plot is adjusted for overdispersion.
```

`ggplot2`

will warn you, as above, if you are excluding any points from your plot.

You can change the plot labels and axis labels easily using the options: `title`

, `x_label`

and `y_label`

.

```
funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE, title = "Vignette funnel plot"
, x_label = "x-axis", y_label = "y-axis") ,
```

```
#> A funnel plot object with 54 points of which 9 are outliers.
#> Plot is adjusted for overdispersion.
```

Since `funnelplotr`

uses `ggplot2`

, you could always extract the plot and alter it manually like any other `ggplot2`

object. The easiest way is to extract it with `plot()`

. Below we’ll add a (completely useless) vertical line to demonstrate adding more elements:

```
# Original funnel plot object
<-
fp funnel_plot(denominator=medpar$prds,numerator=medpar$los
group = medpar$provnum, limit=99 ,label_outliers = TRUE
, Poisson_limits = TRUE)
,
# Extract just the plot
<- plot(fp)
my_plot
# Add an additional geom to plot
+
my_plot geom_vline(aes(xintercept=400), linetype = "dashed", colour="red", size=2)
```