Lode guidance functions

Source: R/lode-guidance-functions.r

These functions control the order of lodes within strata in an alluvial diagram. They are invoked by stat_alluvium() and can be passed to the lode.guidance parameter.

lode_zigzag(n, i)

lode_zagzig(n, i)

lode_forward(n, i)

lode_rightward(n, i)

lode_backward(n, i)

lode_leftward(n, i)

lode_frontback(n, i)

lode_rightleft(n, i)

lode_backfront(n, i)

lode_leftright(n, i)

Arguments

n

Numeric, a positive integer

i

Numeric, a positive integer at most n

Details

Each function orders the numbers 1 through n, starting at index i. The choice of function made in stat_alluvium() determines the order in which the other axes contribute to the sorting of lodes within each index axis. After starting at i, the functions order the remaining axes as follows:

  • zigzag: Zigzag outward from i, starting in the outward direction

  • zigzag: Zigzag outward from i, starting in the inward direction

  • forward: Increasing order (alias rightward)

  • backward: Decreasing order (alias leftward)

  • frontback: Proceed forward from i to n, then backward to 1 (alias rightleft)

  • backfront: Proceed backward from i to 1, then forward to n (alias leftright)

An extended discussion of how strata and lodes are arranged in alluvial plots, including the effects of different lode guidance functions, can be found in the vignette "The Order of the Rectangles" via vignette("order-rectangles", package = "ggalluvial").