Table Transformer: obtain a summary stats table for numeric columns

With any table object, you can produce a summary table that is scoped to the numeric column values. The output summary table will have a leading column called ".param." with labels for each of the nine rows, each corresponding to the following summary statistics:

Minimum ("min")
5th Percentile ("p05")
1st Quartile ("q_1")
Median ("med")
3rd Quartile ("q_3")
95th Percentile ("p95")
Maximum ("max")
Interquartile Range ("iqr")
Range ("range")

Only numerical data from the input table will generate columns in the output table. Column names from the input will be used in the output, preserving order as well.

Usage

tt_summary_stats(tbl)

Arguments

tbl

A data table

obj:<tbl_*> // required

A table object to be used as input for the transformation. This can be a data frame, a tibble, a tbl_dbi object, or a tbl_spark object.

Value

A tibble object.

Examples

Get summary statistics for the game_revenue dataset that is included in the pointblank package.

tt_summary_stats(tbl = game_revenue)
#> # A tibble: 9 x 3
#>   .param. item_revenue session_duration
#>   <chr>          <dbl>            <dbl>
#> 1 min             0                 3.2
#> 2 p05             0.02              8.2
#> 3 q_1             0.09             18.5
#> 4 med             0.38             26.5
#> 5 q_3             1.25             33.8
#> 6 p95            22.0              39.5
#> 7 max           143.               41
#> 8 iqr             1.16             15.3
#> 9 range         143.               37.8

Table transformers work great in conjunction with validation functions. Let's ensure that the maximum revenue for individual purchases in the game_revenue table is less than $150.

tt_summary_stats(tbl = game_revenue) %>%
  col_vals_lt(
    columns = item_revenue,
    value = 150,
    segments = .param. ~ "max"
  )
#> # A tibble: 9 x 3
#>   .param. item_revenue session_duration
#>   <chr>          <dbl>            <dbl>
#> 1 min             0                 3.2
#> 2 p05             0.02              8.2
#> 3 q_1             0.09             18.5
#> 4 med             0.38             26.5
#> 5 q_3             1.25             33.8
#> 6 p95            22.0              39.5
#> 7 max           143.               41
#> 8 iqr             1.16             15.3
#> 9 range         143.               37.8

We see data, and not an error, so the validation was successful!

Let's do another: for in-app purchases in the game_revenue table, check that the median revenue is somewhere between $8 and $12.

game_revenue %>%
  dplyr::filter(item_type == "iap") %>%
  tt_summary_stats() %>%
  col_vals_between(
    columns = item_revenue,
    left = 8, right = 12,
    segments = .param. ~ "med"
  )
#> # A tibble: 9 x 3
#>   .param. item_revenue session_duration
#>   <chr>          <dbl>            <dbl>
#> 1 min             0.4              3.2
#> 2 p05             1.39             5.99
#> 3 q_1             4.49            14.0
#> 4 med            10.5             22.6
#> 5 q_3            20.3             30.6
#> 6 p95            66.0             38.8
#> 7 max           143.              41
#> 8 iqr            15.8             16.7
#> 9 range         143.              37.8

We can get more creative with this transformer. Why not use a transformed table in a validation plan? While performing validations of the game_revenue table with an agent we can include the same revenue check as above by using tt_summary_stats() in the preconditions argument. This transforms the target table into a summary table for the validation step. The final step of the transformation in preconditions is a dplyr::filter() step that isolates the row of the median statistic.

agent <-
  create_agent(
    tbl = game_revenue,
    tbl_name = "game_revenue",
    label = "`tt_summary_stats()` example.",
    actions = action_levels(
      warn_at = 0.10,
      stop_at = 0.25,
      notify_at = 0.35
    )
  ) %>%
  rows_complete() %>%
  rows_distinct() %>%
  col_vals_between(
    columns = item_revenue,
    left = 8, right = 12,
    preconditions = ~ . %>%
      dplyr::filter(item_type == "iap") %>%
      tt_summary_stats() %>%
      dplyr::filter(.param. == "med")
  ) %>%
  interrogate()

Printing the agent in the console shows the validation report in the Viewer. Here is an excerpt of validation report. Take note of the final step (STEP 3) as it shows the entry that corresponds to the col_vals_between() validation step that uses the summary stats table as its target.

This image was generated from the first code example in the `tt_summary_stats()` help file.

Function ID

12-1