# Data structures

Author

Jeffrey R. Stevens

Published

February 6, 2023

## In-class coding

Make a sequence from 0 to 100 in steps of 10.

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Create a repetition of “yes” and “no” with 10 instance of each, alternating between the two. Then make one with 10 “yes” and then 10 “no”.

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Add the argument `n = 10` to `head(mtcars)`. What does this do?

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## Extra coding practice

### Vectors

Create a vector called `dog_names` with the values Bella, Daisy, and Max.

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Create a vector called `sex` with the values Female, Male, and Male.

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Use the index operator to print to console only Daisy and Max from `dog_names`.

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Replace the Daisy entry with Luna and print `dog_names` to console.

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### Lists

Copy/paste and run this code: `(mylist <- list(a = 1:4, b = c(4, 3, 8, 5), c = LETTERS[10:15], d = c("yes", "yes")))`

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Check the data types for each list element individually.

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Check the data types for each list element with one command.

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Combine list elements `a` and `b` into a single vector.

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### Data frames

Create a data frame called `mydf` with three columns: `x`, `y`, and `z` and five rows. For `x` assign any five numbers, for `y` assign any five character strings, and for `z` assign any five logical values.

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Create a data frame called `dogs` that combines the `dog_names` and `sex` vectors and print to console.

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Print to console just Luna’s row.

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Print to console the number of rows in `dogs`.

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