Class3_CodeBasicsIIImportI

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Class 3 Summary

• We finished up coding basics this week by talking about matrices and scripts
  • Matrices

    • A matrix is another kind of R-Object. Matrices are used for math operations, such as linear algebra and solving systems of equations. We won’t work with them that much in this course, but it is important to know how to use them as they can be used in more complex statistical analysis done in R.

      MyMatrix = matrix(c(3:20), nrow = 3, ncol = 6, byrow = FALSE)
      MyMatrix

      ##      [,1] [,2] [,3] [,4] [,5] [,6]
      ## [1,]    3    6    9   12   15   18
      ## [2,]    4    7   10   13   16   19
      ## [3,]    5    8   11   14   17   20

    • Notes

      • R places indicators in square brackets [] to help navigate the matrix.

      • The colon : is a little cheat for making a vector that increases in increments of 1 between the numbers.

        vec = c(4:15)
        vec

        ##  [1]  4  5  6  7  8  9 10 11 12 13 14 15

  • Scripts
    • Scripts were the last concept we covered in coding basics. Scripts are the actual files that one can use to save, edit, and run code. Unfortunately it is hard to demonstrate the use of scripts in this PDF doc, so I suggest watching the recorded lectures to review.
• Importing Data
  • Our first topic moving out of coding basics is how to import our data into R. In this class we will focus on importing excel spreadsheets. It is hard to demonstrate here, so like scripts, I recommend re-watching the recorded lectures.