Simple Introduction to Clojure with Analysis By: Shannon Birchell

 First Class Functions  Inherits concepts from Lisp  Every expression is a function  Functions attempt to be pure (not possible)  Concurrency is very stable  Software Transaction Memory(STM)  Uses JVM  Hybrid  Dynamically run code  REPL  Inherits all Java classes (4k+)

 Primitives Not so interesting: Number, String, Boolean and char  Coercion takes place on the JVM in byte code  Interesting Lisp primitives  List: Linked List without element removal capacities  Vector: like linked list but more efficient (less capabilities)  Keyword: used for Map as key  Map: equivalent to Hashmap  Set: same as mathematics

 Dynamic type binding  Variable Scope  Stack Dynamic  Explicitly stated global scopes  Value bindings are immutable  Values cannot be changed  Mapping are used to transform variables  Enhanced stability and reliability

 Function Declaration  Anonymous function (fn [ ]( … ))  Explicit function (defn [ ] ( <element…))  Functions can be self documented using  Function closure  A function and all its current values can be stored as a variable. It is said, “The function is closed over”

 Some functions  String: (str “hello” “world”) -> hello world  (cons 4 ‘(1 2 3)) ->  (first ‘(1 3 5)) ->1  (doc someFunct) -> description  First class functions  Parameters can be functions (* (+ 1 1) (+ 1 1)) = (* 2 (+ 1 1))=(* 2 2)=4  Return values can be functions  (defn f1 [p1] (fn [p2] ( str p1 p2)))

 Java integration  ( javax.swing.JOptionPane/showMessageDialog nil (str "Hello Everyone"))  Is equivalent to java code: javax.swing.JOptionPane.showMessageDialog(null, "Hello Everyone“);  Dot operator “.” performs java functinality (. String split “,”) -> String.split(“,”);  Most java objects do not work in the dynamic environment

 Readability  Orthogonal structures. (. String contains “hi”) -> String.contains(“hi”);  iteration is done through recursion and is cryptic  Writeability  Highly nested structures require substantial forethought (if(< (+ 1 1) (3/4) “write”))  Highly nested structures unify code into cohesive chunk.  Cost  Different than main stream – learning curve  Free software with good libraries

Overview and analysis of R By Shannon Birchell

 Domain specific  Statistical and numerical analysis  Used as a scripting language  Run commands real time in R environment  R Based on S syntax  Created by Bell Laboratories in 1976  Alternative to Fortran  Static scoped  Imperative language  Class Oriented  Like OO but uses predefined classes

 Primitives  Vectors logical, integer, double, complex, character, or raw  Coercion is used for different vectors of different size + = Logical Error checking reduced!!!  Type coercion is character, integer, double, logic  Implicit type binding  Lists  Behave like a vector without enforcing a type  Keys/Names can be associated with entries  Use brackets with name string to accesses elements

 Matrix  Is a vector that is mapped to the specified dimensions  Coercion done when dim doesn’t match  An associated array  Indexes start with 1  Tables  Matrix with elaborate row and column names  Inherits additional methods: colnames & rownames

 Objects are black box  unlike Java  Objects are implicitly associated with a class  Auto inherit mode and Attribute methods  More that one class may be inherited  There are many built in functions  Associated with classes but for all practical purposes act completely like functions

 Important Functions  Function c() creates a vector  Function list() creates a vector of generic types  Function dim() maps vector to an array  Function plot() graphs a dataset  Creating a objects  “<-” assign to an object  Can assign values, functions or other objects  Creating a vector: x <-c(1,2,3,4)  Creating a list x <- list( “one”, 1, three= ”three” )

 Creating a matrix  array( c(1,0,0,1), dim=c(2,2))-> a :  Creating a function  Default values as parameters x <- function(a, b = 1 ){ return( a + b );} x(1,2) is 3 x(4) is 5  Creating a graph  Plot, box plot, density… etc

 Readability  Black box objects make it difficult to understand what objects can do  Familiar syntax  Writeability  Large number of operators make full language use difficult  Large number of keywords is problematic  Consistent use of expressions make tasks easy  Cost  Syntax is familiar to C and C++  Software and packages are free

 Micheal J. Crawley, “The R Book”, Wiley, 2007  The R Project,

Simple Introduction to Prolog with Analysis By: Shannon Birchell

 Languages is based on first order logic  Queries perform complex analysis on truth statements  Can display true of false at the simplest level  Can display all values that are true

 Atom  A string of characters that is tokenized as an id  Has no other purpose  Scope is global  Numbers  Floats and Integers only  Variables  Starts with a capital letter  Anonymous variable “_”  Scope is rule

 An Axiom is a statement of truth  Immutable – always true “There is a dog call red”  There must be an animal dog : animal(dog).  There must be a name red: name(red).  Rules are axioms with relationships Given the previous example “There is a dog called red”  The relationship that bind “dog” and “red” the verb called Therefore called(x):= name(x), animal(x).

 Unification is how prolog derives the truth of a query  This is done by checking all axioms against rules Object is to make the implication query equal: axiom1, axiom2 axiomN…. rule1, rule2… query ? Rule LHS <- rule RHS <- axioms  Backtracking is the process of performing unification over all possibilities

 Readability  Difficult to understand the relationships  But this is the point!!!  Writeability  Simple statements of fact  Simple syntax  Reliability  Bad query catastrophically fail  Unintended consequences of statements unrealized