Function
0.1 Introduction
Instance of:
0.2 Frequentist
AKA: \(f: X \mapsto Y\), \(f(x)\), map, mapping, linear map, linear function, transformation, morphism
Distinct from:
English: A function from a set X to a set Y is an assignment of an element of Y to each element of X. The set X is the domain, and the set Y is the codomain.
Formalization:
The formalization is annoying in that there are multiple conventions for writing a function which are equivalent.
Psuedo code
f = function(X){
Y=X+1 #some operation
return(Y)
}
Where the domain is all flatoing point numbers and so is the codomain (up to the precision of the computer).
That can also be written.
\[ f: X \mapsto Y \] Where \(f\) is the name of the function, \(\mapsto\) is the “maps to” or “Maplet” symbol.
Cites: Wikipedia ; Wikidata ; Wolfram
Code
library(DBI)
# Create an ephemeral in-memory RSQLite database
#con <- dbConnect(RSQLite::SQLite(), dbname = ":memory:")
#dbListTables(con)
#dbWriteTable(con, "mtcars", mtcars)
#dbListTables(con)
#Configuration failed because libpq was not found. Try installing:
#* deb: libpq-dev libssl-dev (Debian, Ubuntu, etc)
#install.packages('RPostgres')
#remotes::install_github("r-dbi/RPostgres")
#Took forever because my file permissions were broken
#pg_lsclusters
require(RPostgres)
Loading required package: RPostgres
0.3 Bayesian
English: Formalization:
\[ \]
Cites:
Code