String together combinations by joining them with an ampersand (&).

This shiny app is based on an R package that I have developed called eulerr. It generates area-proportional euler diagrams using numerical optimization routines.

Euler diagrams
are generalized venn diagrams for which the requirement that
all intersections be present is relaxed. They are constructed
from a specification of set relationships but may sometimes
fail to display these appropriately. For instance, try giving
the app the specification
`A = 5, B = 3, C = 1, A&B = 2, AB&C = 2`

to see what I mean.

When this happens, eulerr tries to give an indication of
how badly the diagram fits the data through the metrics
*stress*
and
*diag error.*
The latter of these show the largest difference in percentage
points between the specification of any one set combination
and its resulting fit. It is the maximum value of
*region error,*
which is given for each combination. This metric has been
adopted from
a paper by Micallef and Peter Rodgers.
Stress is more difficult to explain, but I advise the
interested reader to read
Leland Wilkinson's excellent paper
for a proper brief.

Finally, I owe a great deal to the aforementioned Wilkinson as well as Ben Frederickson whose work eulerr is inspired by.

*Johan Larsson*

The Shiny app that is hosted here does not completely cover
all the functionality that the R package offers.
The number of sets is for instance limited to five here
but there is no such limitation in the package.
If you want to install the R package, then you need to first
install R.
After this you can simply install the package by calling `install.packages("eulerr")`

.

To read more about the R package, please visit the package page on CRAN.

eulerr is an open-source project that welcomes contributions from anyone who's willing to chip in. Please see the development page for the R package if you are interested in taking part or just want to report an issue with the package. If you find any issues with this site, please visit the development page for the Shiny appplication and file an issue there.

To cite eulerr in publications, please use

A BibTeX entry for LaTeX users is