T-Test: Pairwise (pairwise)

The pairwise implementation performs pairwise t-tests across a set of numeric variables. Each pair of variables is compared independently, and results are presented as a matrix.

Use pairwise() as the variable mapper <var_id> to select this implementation.

Arguments

The following arguments are passed via ... in TTEST():

.paired

Logical. Whether to perform paired comparisons. Default FALSE.

.mu

Numeric. Hypothesized mean or mean difference. Length 1 (applied to all pairs) or one value per variable. Default 0.

.alt

String. One of "two.sided", "greater", or "less". Default "two.sided".

.ci

Numeric. Confidence level. Default 0.95.

Variants

No variants are currently registered for the pairwise path. Use add_variant() to register custom variants at the user or package level.

Pairwise t-test class

By default, it returns a class_ttest_pairwise object inheriting from class_stat_infer. Objects from it are printed as a pairwise matrix via tabstats::pairwise_matrix(). All variants that also return class_ttest_two inherit auto_tidy() and print() automatically. Otherwise, to process outputs:

• print(): Write it down through print from variant().

• tidy(): Use making_tidy() to register a tidy method if needed.

One-sample mode

When pairwise() has equal referred columns, made by direction = "<eq, lteq, gteq>" argument, each variable is tested against its own .mu value rather than against another variable, resonating to a one-sample test. The pairwise t-test output matrix displays diagonal entries only.

See also

Other ttest-implementations: ttest-formula, ttest-on, ttest-xby

Examples

iris |>
    define_model(pairwise(Sepal.Length, Sepal.Width, Petal.Length)) |>
    prepare_test(TTEST) |>
    conclude()
#> 
#> == Model ======================================================================= 
#> 
#> Variable Mapper : pairwise 
#> Args : Sepal.Length, Sepal.Width, Petal.Length 
#>     direction : lt 
#>     n_pairs : 3 
#> 
#> == T-Test ====================================================================== 
#> 
#> 
#> ┌───────────────────────────┐
#> | Layout for Pairwise Matri |
#> ├───────────────────────────┤
#> |         < diff >          |
#> |        < t_stat >         |
#> |         < pval >          |
#> |          < ci >           |
#> └───────────────────────────┘
#> 
#> 
#>                      Welch Two Sample t-test                      
#> ──────────────────────────────────────────────────────────────────
#>   Variable         Sepal.Length      Petal.Length    Sepal.Width  
#> ──────────────────────────────────────────────────────────────────
#>   Sepal.Length                                                    
#>                                                                   
#>                                                                   
#>                                                                   
#> ──────────────────────────────────────────────────────────────────
#>   Petal.Length        -2.085                                      
#>                      -13.098                                      
#>                       <0.001                                      
#>                  [-2.399  -1.772]                                 
#> ──────────────────────────────────────────────────────────────────
#>   Sepal.Width         2.786             0.701                     
#>                       36.463            4.719                     
#>                       <0.001            <0.001                    
#>                   [2.635  2.937]    [0.408  0.994]                
#> ──────────────────────────────────────────────────────────────────