Analysis of Variance - Table of Means

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Creates a table showing the mean of an Outcome variable, by two other variables, where one is shown in the Rows and the other in the Columns. Each row shows a separate one-way analysis of variance, with the variance parameter assumed constant across all of the rows (unless using robust standard errors). If the Outcome is not numeric and if the Rows and Columns are not categorical, they are coerced to such types.

How to Create a Table of Means

  1. Add the object:
    1. In Displayr: Insert > More > Analysis of Variance > Table of Means
    2. In Q: Create > Analysis of Variance > Table of Means
  2. In Inputs > Outcome specify the outcome variable.
  3. Specify the predictor variables in Inputs > Rows annd Inputs > Columns.

Example


Options

The options in the Object Inspector are organized into two tabs: Inputs and Properties.

Inputs

Outcome The variable to be predicted.

Rows A variable containing 2 or more groups. If not categorical, it is converted into categories in the analysis.

Columns A variable containing 2 or more groups. If not categorical, it is converted into categories in the analysis.

Correction The multiple comparisons correction applied when computing the p-values of the post-hoc comparisons.

Robust standard errors Computes standard errors that are robust to violations of the assumption of constant variance. See Robust Standard Errors.

Variable names Displays Variable Names in the output.

Filter The data is automatically filtered using any filters prior to estimating the model.

Weight Where a weight has been set for the R Output, the calibrated weight is used. See Weights in R.

Properties

This tab contains options for formatting the size of the object, as well as the underlying R code used to create the visualization, and the JavaScript code use to customize the Object Inspector itself (see Object Inspector for more details about these options). Additional options are available by editing the code.

More Information

Acknowledgements

The linear model is fitted using the lm and manova functions in R. See Analysis of Variance - One-Way ANOVA for acknowledgements relating to the ANOVAs in the outputs.

Code

form.setHeading('TableOfMeans');
form.dropBox({label: "Outcome", 
            types:["Variable: Numeric, Date, Money, Categorical, OrderedCategorical"], 
            name: "formOutcomeVariable",
            prompt: "Numeric outcome variable, for which means are computed",
            multi:false})
form.dropBox({label: "Rows",
            types:["Variable: Numeric, Date, Money, Categorical, OrderedCategorical"], 
            prompt: "Categorical grouping variable for rows",
            name: "formRows"})
form.dropBox({label: "Columns",
            types:["Variable: Numeric, Date, Money, Categorical, OrderedCategorical"], 
            prompt: "Categorical grouping variable for columns",
            name: "formColumns"})
form.comboBox({label: "Correction", 
              alternatives: [ "None", "False Discovery Rate", "Table FDR", "Tukey Range", "Benjamini & Yekutieli", "Bonferroni", "Free Combinations", "Hochberg", "Holm", "Hommel", "Single-step", "Shaffer", "Westfall"], 
              prompt: "Multiple comparisons correction used when calculating p-values",
              name: "formCorrection", default_value: "Table FDR"})
form.checkBox({label: "Robust standard errors", name: "formRobust", default_value: false,
               prompt: "Compute standard errors that are robust to violations of the assumption of constant variance"})
form.checkBox({label: "Variable names", name: "formNames", default_value: false, prompt: "Whether to use variable names instead of labels"})
library(flipAnalysisOfVariance)

means <- TableOfMeans(QInputs(formOutcomeVariable),
                         QInputs(formRows),
                         QInputs(formColumns),
                         correction = formCorrection,
                         robust.se = formRobust,
                         subset = QFilter,
                         weights = QPopulationWeight,
                         show.labels = !formNames)