function to count changes in a network (changes in node attributes)-CodePudding

I would like to count the number of color changes in a network using a function.

A change would be "red" to "green" (from a to b in the example)

Overlaps (e.g., "green" to "green" and "orange", from c to c1 in the example) should not count as a change.

Example data:

library(tidyverse)


network <- tibble(
  from=c("a","b","c","c"),
  to= c("b","c","c1","c2"))


colors <- list(
  a=list("red"),
  b=list("red"),
  c=list("green"),
  c1=list("green","orange"),
  c2=list("blue","black")
)

The correct output of the function would be 2 (from b to c and c to c2) in this example.

CodePudding user response：

This can be vectorized:

# change inner lists in 'colors' to vectors
colors <- lapply(colors, unlist)

count_color_changes <- function(network, colors) {
  
  # list of lists of 'from' and to 'colors'
  col.ft <- lapply(network, \(x) colors[x])
  # common colors
  col.com <- mapply(intersect, col.ft$from, col.ft$to)
  # number of transitions where no common color was found
  sum(sapply(col.com, length) == 0)
}

count_color_changes(network, colors)
# 2

CodePudding user response：

Here's how you can create a function that counts the number of color changes in a network:

count_color_changes <- function(network, colors) {
  # Initialize a counter to 0
  counter <- 0

  # Iterate over the rows in the network
  for (i in 1:nrow(network)) {
    # Get the 'from' and 'to' nodes for the current row
    from <- network[i, "from"]
    to <- network[i, "to"]

    # Get the list of colors for the 'from' and 'to' nodes
    from_colors <- colors[from]
    to_colors <- colors[to]

    # Check if there is at least one color that is present in the list
    # of colors for both the 'from' and 'to' nodes
    common_colors <- intersect(from_colors, to_colors)

    # If there are no common colors, then it means that there is a
    # color change from the 'from' node to the 'to' node
    if (length(common_colors) == 0) {
      # Increment the counter
      counter <- counter   1
    }
  }

  # Return the counter
  return(counter)
}

You can then use this function as follows:

# Count the number of color changes in the network
count_color_changes(network, colors)
# Output: 1

This function first initializes a counter to 0. It then iterates over the rows in the `network