Type:	Package
Title:	Draw XmR Charts for NHSE/I 'Making Data Count' Programme
Version:	0.1.0
Maintainer:	Christopher Reading <christopher.reading1@nhs.net>
Description:	Provides tools for drawing Statistical Process Control (SPC) charts. This package supports the NHSE/I programme 'Making Data Count', and allows users to draw XmR charts, use change points and apply rules with summary indicators for when rules are breached.
URL:	https://nhs-r-community.github.io/NHSRplotthedots/
License:	MIT + file LICENSE
Encoding:	UTF-8
RoxygenNote:	7.1.2
Imports:	ggplot2, scales, dplyr, rlang, crayon, utils, NHSRdatasets, assertthat, grid
Suggests:	covr, lintr, testthat (≥ 3.0.0), rmarkdown, knitr, mockery, withr, spelling
VignetteBuilder:	knitr
Config/testthat/edition:	3
Language:	en-US
NeedsCompilation:	no
Packaged:	2021-11-02 18:47:02 UTC; Giselle
Author:	Christopher Reading [cre, aut], Simon Wellesley-Miller [aut], Zoë Turner [aut], Tom Jemmett [aut], Tom Smith [aut], Chris Mainey [aut], John MacKintosh [aut], NHS-R community [cph]
Repository:	CRAN
Date/Publication:	2021-11-03 20:20:10 UTC

Create ggplot2

Description

Creates a ggplot2 object using the parameters passed in.

Usage

ptd_create_ggplot(
  x,
  point_size = 4,
  percentage_y_axis = FALSE,
  main_title,
  x_axis_label,
  y_axis_label,
  fixed_x_axis_multiple = TRUE,
  fixed_y_axis_multiple = TRUE,
  x_axis_date_format = "%d/%m/%y",
  x_axis_breaks = NULL,
  y_axis_breaks = NULL,
  icons_size = 8L,
  icons_position = c("top right", "bottom right", "bottom left", "top left", "none"),
  colours = ptd_spc_colours(),
  theme_override = NULL,
  break_lines = c("both", "limits", "process", "none"),
  ...
)

Arguments

Value

The ggplot2 object

Rebase

Description

Produces an object that can be used for rebasing an SPC chart. This method provides two different ways to rebase:

1. You can either provide a single vector of dates, which will rebase every facet of an SPC with the same dates

2. You can provide named vectors of dates, where the names correspond to the names of the facets, in order to rebase a facetted chart

Usage

ptd_rebase(...)

Arguments

Value

a list

Examples

# if you aren't using a facetted chart, or you want to rebase each facet at the same dates, then
# you can simply call this method with a vector of dates. For example, to rebase on the 1^st^
# January 2020 and 22^nd^ March 2020:

ptd_rebase(as.Date(c("2020-01-01", "2020-03-22")))

# if you are using a facetted chart, and wish to rebase each facet with different dates, then
# you can call this method, naming each vector of dates with the name of the facet. If there are
# facet's that you don't need to rebase you can simply ignore them. For example, if you had a
# chart with facets "a", "b", and "c", and you wanted to rebase "a" on the 1^st^ January 2020,
# and "b" on the 22^nd^ March 2020:

ptd_rebase(
  "a" = as.Date("2020-01-01"),
  "b" = as.Date("2020-03-22")
)

SPC Plotting Function

Description

ptd_spc returns a plot object or data table with SPC values using NHSI 'plot the dots' logic.

Usage

ptd_spc(
  .data,
  value_field,
  date_field,
  facet_field,
  rebase = ptd_rebase(),
  fix_after_n_points = NULL,
  improvement_direction = "increase",
  target = ptd_target(),
  trajectory,
  screen_outliers = TRUE
)

Arguments

Details

This function is designed to produce consistent SPC charts across Information Department reporting, according to the 'plot the dots' logic produced by NHSI. The function can return either a plot or data frame.

Value

A ggplot2 object of the spc charts. This will automatically print the plot, but can also be saved as an object if you want to manipulate it further.

Examples

library(NHSRdatasets)
library(dplyr)
data("ae_attendances")

# Pick a trust at random to look at their data for two years
trust1 <- subset(ae_attendances, org_code == "RJZ" & type == 1)

# Basic chart with improvement direction decreasing
ptd_spc(trust1,
  value_field = breaches, date_field = period,
  improvement_direction = "decrease"
)

# Pick a few trust, and plot individually using facet
# Also set the x-axis scale to vary for each and date groups to 3 months
orgs <- c("RAS", "RJZ", "RR1", "RJC", "RQ1")
trusts4 <- filter(ae_attendances, org_code %in% orgs, type == 1)

s <- ptd_spc(trusts4,
  value_field = breaches, date_field = period, facet_field = org_code,
  improvement_direction = "decrease"
)
plot(s, fixed_y_axis_multiple = FALSE, x_axis_breaks = "3 months")

# Save the first chart as an object this time then alter the ggplot theme
my_spc <- ptd_spc(trust1,
  value_field = "breaches", date_field = "period",
  improvement_direction = "decrease"
)

plot(my_spc) + ggplot2::theme_classic()

SPC Colours

Description

Produces a list of colours that controls the geoms in the plot

Usage

ptd_spc_colours(
  common_cause = "#7B7D7D",
  special_cause_improvement = "#289de0",
  special_cause_neutral = "#361475",
  special_cause_concern = "#fab428",
  value_line = "#7B7D7D",
  mean_line = "#000000",
  lpl = "#7B7D7D",
  upl = "#7B7D7D",
  target = "#de1b1b",
  trajectory = "#361475"
)

Arguments

Value

a list of colours

Target

Description

Produces an object that can be used for adding Targets to an SPC chart. This method provides two different ways to add a target:

1. You can either provide a single value, which will apply the same target to every facet of an SPC

2. You can provide named values of targets, where the names correspond to the names of the facets, in order to have different targets for each facet

Usage

ptd_target(...)

Arguments

Details

This function is a helper to provide data in the correct format for use with ptd_spc(). See Value section for details of return type. If you are trying to do something like ptd_spc(list_of_values) then you can skip using the function and just use list_of_values, so long as the list meets the requirements as listed above.

Value

returns either:

• a single numeric value, in this case all facets in the plot will use this target value

• a named list of single numeric values, where each item is named as for one of the facet's in the plot. If a facet isn't specified then it will not have a target

Examples

# if you aren't using a facetted chart, or you want to use the same target for each facet, you
# can simply call this method with a single value. For example, to use a target of 90%:

ptd_target(0.9)

# if you are using a facetted chart, and wish to use a different target for each facet, then you
# can call this method, naming each value with the name of the facet. Any facet that isn't listed
# will not have a target applied to it.

# For example, to apply a target of 25 to the "a" facet and 10 to the "b" facet:

ptd_target(
  "a" = 25,
  "b" = 10
)

# If you already have your data in a list, you do not need to use ptd_target(). But, if you
# wanted to check that your values are valid, you could call it like so:

my_targets <- list("a" = 25, "b" = 10)
do.call(ptd_target, my_targets)

# or, if your targets are in a numeric vector
my_targets <- c("a" = 25, "b" = 10)
do.call(ptd_target, as.list(my_targets))