# install.packages("devtools") devtools::install_github("njtierney/visdat")
Initially inspired by
vis_dat helps you visualise a dataframe and “get a look at the data” by displaying the variable classes in a dataframe as a plot with
vis_dat, and getting a brief look into missing data patterns using
visdat was chosen as I think in the future it could be integrated with
testdat. The idea being that first you visualise your data (
visdat), then you run tests from
testdat to fix them.
There are two main commands in the
vis_dat() visualises a dataframe showing you what the classes of the columns are, and also displaying the missing data.
vis_miss() visualises just the missing data, and allows for missingness to be clustered and columns rearranged.
vis_miss() is similar to
missing.pattern.plot from the
mi package. Unfortunately
missing.pattern.plot is no longer in the
mi package (as of 14/02/2016).
You can read more about visdat in the vignette, “using visdat”“.
Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.
Let’s see what’s inside the
airquality dataset from base R, which contains information about daily air quality measurements in New York from May to September 1973. More information about the dataset can be found with
The plot above tells us that R reads this dataset as having numeric and integer values, with some missing data in
Solar.R. The classes are represented on the legend, and missing data represented by grey. The column/variable names are listed on the x axis.
vis_dat sorts the columns according to the type of the data in the vectors. You can turn this off by setting
sort_type = FALSE.
vis_dat(airquality, sort_type = FALSE)
To demonstrate what visdat looks like when you have different kinds of data, we can look at the dataset
typical_data, provided within
visdat, and created with the excellent
We can also look into using even wider data, looking at
We can explore the missing data further using
The percentages of missing/complete in
vis_miss are accurate to 1 decimal place.
You can cluster the missingness by setting
cluster = TRUE.
vis_miss(airquality, cluster = TRUE)
The columns can also just be arranged by columns with most missingness, by setting
sort_miss = TRUE.
vis_miss(airquality, sort_miss = TRUE)
vis_miss indicates when there is a very small amount of missing data at <0.1% missingness.
test_miss_df <- data.frame(x1 = 1:10000, x2 = rep("A", 10000), x3 = c(rep(1L, 9999), NA)) vis_miss(test_miss_df)
vis_miss will also indicate when there is no missing data at all.
Thank you to Ivan Hanigan who first commented this suggestion after I made a blog post about an initial prototype
ggplot_missing, and Jenny Bryan, whose tweet got me thinking about
vis_dat, and for her code contributions that removed a lot of errors.
Thank you to Hadley Wickham for suggesting the use of the internals of
readr to make
Thank you to Miles McBain for his suggestions on how to improve
vis_guess. This resulted in making it at least 2-3 times faster.
Thanks also to Carson Sievert for writing the code that combined
visdat, and for Noam Ross for suggesting this in the first place.