R

   I will most likely get the equipment data by the end of December. My mentor did say that I may not get it because it is hard to get classified information passed the security department at the marines. If I end up not getting it, my mentor is going to generate random numbers so that I could build my function. In theory, my code should work on the actual data.

   I learned more about the R programming language. I need to be really comfortable with it so that I won't struggle with creating the algorithm as much. I reviewed the basic methods.

   The print method allows me to view my data at any point I want. All I have to do is print it. That is useful because I can check the status of my data frequently, so I can see if I made a mistake anywhere in the process.

   The cat function allows me to print multiple objects, something that the print function cannot do. However, it cannot print " compound data structures such as matrices and lists."

   To instantiate a variable, use <- or -> to set it to any value you want. You can even change the variable from an integer to a list to a String. <<- makes the variable a global variable.

   The rm function deletes variables. You cannot undo this action!

   The c(...) function allows me to create vectors. It works with both vectors and non-vectors.


   Section 2.6 of the R Cookbook discusses coding basic statistics in R.

      "Use one of these functions as applies, assuming that x and y are vectors:
      • mean(x)
      • median(x)
      • sd(x)
      • var(x)
      • cor(x, y)
      • cov(x, y)"

   The cor(x,y) function finds the correlation and cov(x,y) finds the covariance.

Below is a table from the R Cookbook that lists the operator precedence in R.

"Table 2-1. Operator precedence
Operator                                 Meaning                                                See also
[ [[                                         Indexing                                                Recipe 2.9
:: :::                            Access variables in a name space
$ @                        Component extraction, slot extraction
^                                  Exponentiation (right to left)
- +                           Unary minus and plus
:                                          Sequence creation                            Recipe 2.7, Recipe 7.14
%any%                           Special operators                                         Discussion
* /                                     Multiplication, division                             Discussion
+ -                                 Addition, subtraction
== != < > <= >=                 Comparison                                            Recipe 2.8
!                                      Logical negation
& &&                        Logical “and”, short-circuit “and”
| ||                                 Logical “or”, short-circuit “or”
~                                    Formula                                                       Recipe 11.1
-> ->>                            Rightward assignment                              Recipe 2.2
=                               Assignment (right to left)                                  Recipe 2.2
<- <<-                         Assignment (right to left)                            Recipe 2.2
?                                  Help                                                             Recipe 1.7

"


MORE OPERATORS
"%%      Modulo operator
%/%     Integer division
%*%    Matrix multiplication
%in%   Returns TRUE if the left operand occurs in its right operand; FALSE otherwise"


DEFINING A FUNCTION
"function(param1, ..., paramN) {
expr1
.
.
.
exprM
}"





Sources Used:

Teetor, P. (2011). R Cookbook [PDF file]. Sebastopol, California: O'Reilly Media, Inc. Retrieved from My Mentor. 

http://stanford.edu/~jgrimmer/RDataManagement.pdf