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Random Walk Helper

Source: R/helpers.R
rand_walk_helper.Rd

A function to help build random walks by mutating a data frame.

Usage

rand_walk_helper(.data, .value)

Arguments

.data

The data frame to mutate.

.value

The .initial_value to use. This is passed from the random walk function being called by the end user.

Value

A modified data frame/tibble with the following columns added:

  • cum_sum: Cumulative sum of y.

  • cum_prod: Cumulative product of y.

  • cum_min: Cumulative minimum of y.

  • cum_max: Cumulative maximum of y.

  • cum_mean: Cumulative mean of y.

Details

A function to help build random walks by mutating a data frame. This mutation adds the following columns to the data frame: cum_sum, cum_prod, cum_min, cum_max, and cum_mean. The function is used internally by certain functions that generate random walks.

See also

Other Utility Functions: confidence_interval(), convert_snake_to_title_case(), generate_caption(), get_attributes(), rand_walk_column_names(), running_quantile(), std_cum_max_augment(), std_cum_mean_augment(), std_cum_min_augment(), std_cum_prod_augment(), std_cum_sum_augment(), subset_walks()

Author

Steven P. Sanderson II, MPH

Examples

df <- data.frame(
  walk_number = factor(rep(1L:25L, each = 30L)),
  x = rep(1L:30L, 25L),
  y = rnorm(750L, 0L, 1L)
  )

rand_walk_helper(df, 100)
#> # A tibble: 750 × 8
#>    walk_number     x       y cum_sum cum_prod cum_min cum_max cum_mean
#>    <fct>       <int>   <dbl>   <dbl>    <dbl>   <dbl>   <dbl>    <dbl>
#>  1 1               1 -2.09      97.9 -109.       97.9    97.9     97.9
#>  2 1               2 -0.168     97.7  -90.3      97.9    99.8     98.9
#>  3 1               3 -0.890     96.9   -9.90     97.9    99.8     99.0
#>  4 1               4  0.272     97.1  -12.6      97.9   100.      99.3
#>  5 1               5  0.874     98.0  -23.6      97.9   101.      99.6
#>  6 1               6 -0.775     97.2   -5.32     97.9   101.      99.5
#>  7 1               7  0.497     97.7   -7.96     97.9   101.      99.7
#>  8 1               8 -0.887     96.8   -0.899    97.9   101.      99.6
#>  9 1               9 -0.0622    96.8   -0.844    97.9   101.      99.6
#> 10 1              10 -1.31      95.5    0.259    97.9   101.      99.5
#> # ℹ 740 more rows