64 lines
917 B
Plaintext
64 lines
917 B
Plaintext
---
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layout: default
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title: Data structures
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---
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# Data structures
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Might be quite brief.
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Atomic vectors and lists + data frames.
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Most important data types:
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* logical
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* integer & double
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* character
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* date
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* date time
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* factor
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<http://adv-r.had.co.nz/OO-essentials.html>
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Every vector has three key properties:
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1. Type: e.g. integer, double, list. Retrieve with `typeof()`.
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2. Length. Retrieve with `length()`
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3. Attributes. A named of list of additional metadata. With the `class`
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attribute used to build more complex data structure (like factors and
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dates) up from simpler components. Get with `attributes()`.
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## Atomic vectors
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### Doubles
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```{r}
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sqrt(2) ^ 2 - 2
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0/0
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1/0
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-1/0
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mean(numeric())
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```
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## Non-atomic vectors
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`class()`
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### Factors
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(Since won't get a chapter of their own)
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### Dates
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### Date times
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## Lists
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## Data frames
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## Subsetting
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Not sure where else this should be covered.
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