NEWS

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qcc 3.0

• Added the bias-corrected "MSSD" estimator to sd.xbar.one(), available through std.dev = "MSSD" in individuals, EWMA, and CUSUM charts.
• Added all eight Nelson rules, selectable with rule.set = "nelson" in qcc() and qccRules().
• Added overall process performance indices (Pp, Pp_l, Pp_u, Pp_k, and Ppm) and their confidence limits to processCapability().
• Added exported, vectorized d2(), d3(), and c4() functions for bias-correction constants and moments of the range distribution, supporting sample sizes beyond the former table limits and higher precision.
• Chart defaults now use standard R options with a qcc. prefix, for example options(qcc.add.stats = FALSE). qcc.options() is retained as a compatibility interface.
• Fixed sd.xbar.one() handling of missing observations: the "MR" estimator removes missing values before forming moving ranges, and the "SD" estimator uses the non-missing sample size for bias correction.
• Fixed processCapability() returning NULL for nobs and returning NA for Cp_k when only one specification limit is supplied.
• Fixed ewmaSmooth() accepting negative lambda values.
• Fixed phase-II filtering in EWMA and CUSUM plots with chart.all = FALSE when xtime contains dates.
• Fixed causeEffectDiagram() omitting branches or subcause labels when the number of causes is odd.
• Improved chart theming. Statistics footers now have section headings, aligned labels and values and correctly rendered mathematical labels.
• Migrated documentation and namespace generation to roxygen2.
• The minimum supported R version is now 4.4.
• Modification of rules for out-of-control points. A subset of Western Eletric Rules (WER) have been implemented. See qccRules().
• All functions in qcc now return an object with associated print, summary, and plot methods.
• Several modifications to plot and print appearances. In particular graphs are produced using ggplot2 package, with layout obtained using patchworks packakge, and print/summary uses cli package.
• Added function describe() to statistically describe variables in a data.frame according to the type.
• qccGroups() now has first argument data to extract variables from a data frame.
• sd.p() calculation now takes into sizes.
• Removed usage of attach/detach from all examples and documentation.
• plot.qcc() allows to use as.Date() objects along x-axis
• Add option to remove the title from all plots using title = NULL.
• Plotting single data values does not issue an error.

qcc 2.7 (2017-07-11)

• Created an html vignette entitled "A quick tour of qcc".
• Moved R News paper to documentation.
• Removed demos.
• Improved appearance of graphs.
• Control limits for p and np charts computed based on binomial quantiles (and not on normal approximation).
• Control limits for c chart computed based on Poisson quantiles (and not on normal approximation).
• Added head.start argument to cusum function.
• Implemented OC curves for R and S charts.
• Make xbar OC curves when confidence.level is used.
• Fix a bug in sd.u
• Fix typos in the documentation.
• Fix a bug in cex labels.
• Add a link in the qcc-package.Rd help page to yhat blog post describing how to implement the Western Eletric Rules (WER).
• pareto.chart() function now returns an object of class paretoChart with associated print and plot method.
• Included a link in the qcc-package.Rd to R News article.

qcc 2.6 (2014-10-07)

• Allow one sided specification limit in process.capability().
• Add an example in qcc man page showing how to add warning limits.

qcc 2.5 (2014-07-01)

• Bug fix for plotting np-chart with variable sample size.
• Pdf files (previously included as vignettes) moved to inst/doc with corresponding index.html.

qcc 2.4

• Added a demo showing how to extend the package by defining a new control chart, i.e. the standardized p chart.
• Fix a bug in qcc() to allow a user defined control chart.

qcc 2.3 (2014-02-25)

• Fix a bug in pareto.chart when compute percentages based on quantiles for the right axis. Added the argument plot which if sets to FALSE won't produce the chart but only return a frequency summary table.
• Added R-news article as vignette.
• Modified the qcc.option() function so changing a parameter in .qcc.options inside a function will make the modification persistent even outside the function environment.
• Bug fix in cusum function if a vector is provided as input with sizes > 1 but no std.dev.

qcc 2.2 (2011-09-30)

• Removed code producing plots on process capability.

qcc 2.1

• Some modifications and bug fixes to pareto.chart() function.

qcc 2.0 (2009-10-21)

• Multivariate control charts (T^2, T^2 for individual observations, Ellipse chart for bivariate data) have been included.
• sd.xbar.one now allows to estimate the standard deviation by using the moving range (default as in the previous versions) or the method suggested by Ryan (2000) using the scaled std deviation of the observations.
• cusum() and ewma() have been rewritten to be called directly with data and arguments. No need to create a qcc object before.
• Added a NAMESPACE, exporting all functions with names not starting with a dot ..

qcc 1.3 (2008-10-11)

• Redefined std.dev argument in qcc() function. It now allows to give a numerical value or a sting identifying a method for estimating the standard deviation of a continuous process variable. Thus, these methods are only available to "xbar", "R", and "S" charts. For details see help(qcc). Functions involved in such change are std.xbar(), std.R(), std.S(), whereas the other sd.* functions only have "..." argument added.
• If xbar chart is needed and the number of observations is larger than 25 use "RMSDF" method for computing process standard deviation.
• Fixed bug in highlighting violating runs and out of control points when chart.all = FALSE.
• Changed background color for Control Charts.
• Changed position of control limit labels in Shewhat and CusSum charts.

qcc 1.2 (2007-01-04)

• Added functions to plot Shewhart g chart (geometric distribution): stats.g(), sd.g(), limits.g().
  Contributed by Greg Snow ([email protected]).
• Bug fix in violating.runs()
• Changes in qcc.options():
  • run.length set by default at 7 (it was 5 previously);
  • font.stats and cex.stats control font and character expansion used to draw text at the bottom of control charts.
• Added qcc_Rnews.pdf paper in doc directory

qcc 1.1 (2004-06-21)

• Fixed some minor bugs
• Reworked on par settings to allow multiple figures
• Corrected typos in *.Rd files

qcc 1.0 (2004-03-04)

• Package release on CRAN.