report_sample: add effective n (closes #306)

[rempsyc]

Closes #306

---

devtools::load_all("D:/github/forks/report")
#> ℹ Loading report

report_sample(airquality, n = TRUE)
#> # Descriptive Statistics
#> 
#> Variable             |             Summary
#> ------------------------------------------
#> Mean Ozone (SD), n   |  42.13 (32.99), 116
#> Mean Solar.R (SD), n | 185.93 (90.06), 146
#> Mean Wind (SD), n    |    9.96 (3.52), 153
#> Mean Temp (SD), n    |   77.88 (9.47), 153
#> Mean Month (SD), n   |    6.99 (1.42), 153
#> Mean Day (SD), n     |   15.80 (8.86), 153

report_sample(airquality, group_by = "Month", n = TRUE)
#> # Descriptive Statistics
#> 
#> Variable             |            5 (n=31) |           6 (n=30) |           7 (n=31) |           8 (n=31) |           9 (n=30) |       Total (n=153)
#> ----------------------------------------------------------------------------------------------------------------------------------------------------
#> Mean Ozone (SD), n   |   23.62 (22.22), 26 |   29.44 (18.21), 9 |  59.12 (31.64), 26 |  59.96 (39.68), 26 |  31.45 (24.14), 29 |  42.13 (32.99), 116
#> Mean Solar.R (SD), n | 181.30 (115.08), 27 | 190.17 (92.88), 30 | 216.48 (80.57), 31 | 171.86 (76.83), 28 | 167.43 (79.12), 30 | 185.93 (90.06), 146
#> Mean Wind (SD), n    |    11.62 (3.53), 31 |   10.27 (3.77), 30 |    8.94 (3.04), 31 |    8.79 (3.23), 31 |   10.18 (3.46), 30 |    9.96 (3.52), 153
#> Mean Temp (SD), n    |    65.55 (6.85), 31 |   79.10 (6.60), 30 |   83.90 (4.32), 31 |   83.97 (6.59), 31 |   76.90 (8.36), 30 |   77.88 (9.47), 153
#> Mean Day (SD), n     |    16.00 (9.09), 31 |   15.50 (8.80), 30 |   16.00 (9.09), 31 |   16.00 (9.09), 31 |   15.50 (8.80), 30 |   15.80 (8.86), 153

Note: Failing tests appear unrelated to the current PR.

[IndrajeetPatil]

Nice work, @rempsyc! Thanks.

Wouldn't it be better if we default to n = TRUE?

[rempsyc]

Thanks! I wasn't sure if we should set it as default or not since in many data sets there is no missing data at all so that information will be very redundant, and it makes the table larger and slightly less readable. I can change it if you still think it should be default, WDYT?

Also I couldn't find any tests for this function... I'm going to write some then. And should I be using mostly snapshots here as well?

[IndrajeetPatil]

Ah, yes, that's a good point. Okay, let's stick to n = FALSE then.

And, yes, please feel free to add some snapshot tests for this function.

[rempsyc]

Added snapshot tests; all tests for report_sample pass. However, I have commented tests for the weights argument as I don't understand what I need to pass it. It says a character vector indicating the name of a potential weight-variable, but my attempts so far were not successful, as I am not familiar with weighting procedures generally.

[IndrajeetPatil]

LGTM, thanks.

We can come back to the weights issue later.