Visualization Workflows

Facet Groups

Count Small Multiples

Faceting splits one data set into panels so each group can be compared separately.

Program

Play the script to switch grouping strategies and count how many panels would appear.

group_choice
facet_groups.R
Replay: real traced execution (multi-file project)
group_choice <- 2
region <- c("north", "south", "north", "east")
group <- c("region", "single", "pair")[group_choice]
facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))
panels <- length(unique(facet))
label <- paste(group, panels, sep = ":")
cat(label, "\n", sep = "")

group_choice <- 1
region <- c("north", "south", "north", "east")
group <- c("region", "single", "pair")[group_choice]
facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))
panels <- length(unique(facet))
label <- paste(group, panels, sep = ":")
cat(label, "\n", sep = "")

group_choice <- 3
region <- c("north", "south", "north", "east")
group <- c("region", "single", "pair")[group_choice]
facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))
panels <- length(unique(facet))
label <- paste(group, panels, sep = ":")
cat(label, "\n", sep = "")

  1. group_choice ← 2

    1group_choice <- 22region <- c("north", "south", "north", "east")
    values this step2group_choice

  2. region ← north, south, north, east

    1group_choice <- 22region <- c("north", "south", "north", "east")3group <- c("region", "single", "pair")[group_choice]
    values this stepnorth, south, north, eastregion

  3. group ← single

    2region <- c("north", "south", "north", "east")3group <- c("region", "single", "pair")[group_choice]4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))
    values this stepsinglegroup2group_choice

  4. facet ← all, all, all, all

    3group <- c("region", "single", "pair")[group_choice]4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))5panels <- length(unique(facet))
    values this stepall, all, all, allfacetsinglegroup

  5. panels ← 1

    4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))5panels <- length(unique(facet))6label <- paste(group, panels, sep = ":")
    values this step1panelsall, all, all, allfacet

  6. label ← single:1

    5panels <- length(unique(facet))6label <- paste(group, panels, sep = ":")7cat(label, "\n", sep = "")
    values this stepsingle:1labelsinglegroup1panels

  7. cat(label, " ", sep = "")

    6label <- paste(group, panels, sep = ":")7cat(label, "\n", sep = "")
    outputsingle:1
    values this stepsingle:1label

  1. group_choice ← 1

    1group_choice <- 12region <- c("north", "south", "north", "east")
    values this step1group_choice

  2. region ← north, south, north, east

    1group_choice <- 12region <- c("north", "south", "north", "east")3group <- c("region", "single", "pair")[group_choice]
    values this stepnorth, south, north, eastregion

  3. group ← region

    2region <- c("north", "south", "north", "east")3group <- c("region", "single", "pair")[group_choice]4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))
    values this stepregiongroup1group_choice

  4. facet ← north, south, north, east

    3group <- c("region", "single", "pair")[group_choice]4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))5panels <- length(unique(facet))
    values this stepnorth, south, north, eastfacetregiongroup

  5. panels ← 3

    4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))5panels <- length(unique(facet))6label <- paste(group, panels, sep = ":")
    values this step3panelsnorth, south, north, eastfacet

  6. label ← region:3

    5panels <- length(unique(facet))6label <- paste(group, panels, sep = ":")7cat(label, "\n", sep = "")
    values this stepregion:3labelregiongroup3panels

  7. cat(label, " ", sep = "")

    6label <- paste(group, panels, sep = ":")7cat(label, "\n", sep = "")
    outputregion:3
    values this stepregion:3label

  1. group_choice ← 3

    1group_choice <- 32region <- c("north", "south", "north", "east")
    values this step3group_choice

  2. region ← north, south, north, east

    1group_choice <- 32region <- c("north", "south", "north", "east")3group <- c("region", "single", "pair")[group_choice]
    values this stepnorth, south, north, eastregion

  3. group ← pair

    2region <- c("north", "south", "north", "east")3group <- c("region", "single", "pair")[group_choice]4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))
    values this steppairgroup3group_choice

  4. facet ← A, A, B, B

    3group <- c("region", "single", "pair")[group_choice]4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))5panels <- length(unique(facet))
    values this stepA, A, B, Bfacetpairgroup

  5. panels ← 2

    4facet <- switch(group, region = region, single = rep("all", length(region)), pair = c("A", "A", "B", "B"))5panels <- length(unique(facet))6label <- paste(group, panels, sep = ":")
    values this step2panelsA, A, B, Bfacet

  6. label ← pair:2

    5panels <- length(unique(facet))6label <- paste(group, panels, sep = ":")7cat(label, "\n", sep = "")
    values this steppair:2labelpairgroup2panels

  7. cat(label, " ", sep = "")

    6label <- paste(group, panels, sep = ":")7cat(label, "\n", sep = "")
    outputpair:2
    values this steppair:2label
facet A facet key assigns each row to a panel.
unique panels `length(unique(facet))` counts how many panels are needed.
group strategy Changing the grouping strategy changes the chart layout without changing the data rows.