I'm trying to make a formula and I got the error: $ operator not defined for this S4 class with R. First of all, what is a S4 class? What am I doing wrong
dot-operator
clash
uipopovercontroller
post-install
deferred-execution
svelte-intersection-observer
strongly-typed-dataset
sqlx
entity-linking
mouseevent
solr5
teststand
truthiness
maven-javadoc-plugin
microk8s
http-archive
cancel-button
glibc
jscharts
jquery-ui-datepicker
malsup-ajax-form
organizational-chart
rworldmap
svn
dhis-2
elastic-stack
automapper-4
joblib
mysqladmin
hyperref
