29 lines
786 B
Plaintext
29 lines
786 B
Plaintext
---
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layout: default
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title: Data transformation
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output: bookdown::html_chapter
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---
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# Data transformation
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## Missing values
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* Why `NA == NA` is not `TRUE`
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* Why default is `na.rm = FALSE`.
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## Data types
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Overview of different data types and useful summary functions for working with them. Strings and dates covered in more detail in future chapters.
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Need to mention `typeof()` vs. `class()` mostly in context of how date/times and factors are built on top of simpler structures.
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### Logical
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When used with numeric functions, `TRUE` is converted to 1 and `FALSE` to 0. This makes `sum()` and `mean()` particularly useful: `sum(x)` gives the number of `TRUE`s in `x`, and `mean(x)` gives the proportion.
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### Numeric (integer and double)
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### Strings (and factors)
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### Date/times
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