Merge separate divergent size and fill (or color) legends in ggplot showing absolute magnitude with-CodePudding

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I came up with dummy dataset which has the same structure as my dataset, to get a reproducible example:

a1 <- c(-2, 2, 1, 0, 0.5, -0.5) a2 <- c(-2, -2, -1.5, 2, 1, 0) a3 <- c(1.5, 2, 1, 2, 0.5, 0) a4 <- c(2, 0.5, 0, 1, -1.5, 0.5) cond1 <- c("A", "B", "A", "B", "A", "B") cond2 <- c("L", "L", "H", "H", "S", "S") df <- data.frame(cond1, cond2, a1, a2, a3, a4) #some data munging df <- df %>% pivot_longer(names_to = "animal", values_to = "FC", cols = c(a1:a4)) %>% mutate(across(c("cond1", "cond2", "animal"), as.factor)) %>% mutate(fillCol = case_when(FC < 0 ~ "decrease", FC > 0 ~ "increase", FC == 0 ~ "no_change")) # plot 1 plt1 <- ggplot(df, aes(x = cond2, y = animal)) geom_point(aes(size = abs(FC), color = FC)) scale_color_gradient2(low='blue', mid='white', high='red', limits=c(-2,2), breaks=c(-2, -1, 0, 1, 2)) facet_wrap(~cond1) plt1 #plot 2 plt2 <- ggplot(df, aes(x = cond2, y = animal)) geom_point(aes(size = abs(FC), color = factor(FC))) facet_wrap(~cond1) plt2 #plot 3 cols <- c("decrease" = "blue", "no_change" = "white", "increase" = "red") plt3 <- ggplot(df, aes(x = cond2, y = animal)) geom_point(aes(size = abs(FC), color = fillCol)) scale_color_manual(name = "FC", values = cols, labels = c("< 0", "0", "> 0"), guide = "legend") facet_wrap(~cond1) plt3

So the result should be looking basically like plt3 but the legend should be something looking like merging those two legends in plt2. The smallest point would be zero in the middle and increasingly bigger points to negative and positive direction, with colors red = positive, blue = negative, white = zero and the labels on the legends showing the actual numbers. I was tasked with this, but I can not figure it out. This is my first question on Stackoverflow so no images :( . I am relatively new to r.

Thank you!

Edit 12/08/2021 Per @jared_mamrot kind reply below, it only works if the values in the FC variable are somehow regular. But when I change some numbers it shows as a warning and won't show the point on plot. Is it possible to define manual scale with ranges of values or bin it somehow? Example with changed values:

a1 <- c(-2, 2, 1.4, 0, 0.8, -0.5) a2 <- c(-2, -2, -1.5, 2, 1, 0) a3 <- c(1.8, 2, 1, 2, 0.6, 0.4) a4 <- c(2, 0.2, 0, 1, -1.2, 0.5) cond1 <- c("A", "B", "A", "B", "A", "B") cond2 <- c("L", "L", "H", "H", "S", "S") df <- data.frame(cond1, cond2, a1, a2, a3, a4) df <- df %>% pivot_longer(names_to = "animal", values_to = "FC", cols = c(a1:a4)) %>% mutate(across(everything(), as.factor)) plt4 <- ggplot(df, aes(x = cond2, y = animal, color = FC, size = FC)) geom_point() scale_size_manual(values = c(10,8,6,4,3,4,6,8,10), breaks = seq(-2, 2, 0.5), limits = factor(seq(-2, 2, 0.5), levels = seq(-2, 2, 0.5))) scale_color_manual(values = c("-2" = "#03254C", "-1.5" = "#1167B1", "-1" = "#187BCD", "-0.5" = "#2A9DF4", "0" = "white", "0.5" = "#FAD65F", "1" = "#F88E2A", "1.5" = "#FC6400", "2" = "#B72C0A"), breaks = seq(-2, 2, 0.5), limits = factor(seq(-2, 2, 0.5), levels = seq(-2, 2, 0.5))) facet_wrap(~cond1) plt4

> Warning message: > Removed 7 rows containing missing values (geom_point).

CodePudding user response：

One potential solution is to specify the values manually for each scale, e.g.

library(tidyverse) a1 <- c(-2, 2, 1, 0, 0.5, -0.5) a2 <- c(-2, -2, -1.5, 2, 1, 0) a3 <- c(1.5, 2, 1, 2, 0.5, 0) a4 <- c(2, 0.5, 0, 1, -1.5, 0.5) cond1 <- c("A", "B", "A", "B", "A", "B") cond2 <- c("L", "L", "H", "H", "S", "S") df <- data.frame(cond1, cond2, a1, a2, a3, a4) #some data munging df %>% pivot_longer(names_to = "animal", values_to = "FC", cols = c(a1:a4)) %>% mutate(across(everything(), as.factor)) %>% ggplot(aes(x = cond2, y = animal, color = FC, size = FC)) geom_point() scale_size_manual(values = c(10,8,6,4,3,4,6,8,10), breaks = seq(-2, 2, 0.5), limits = factor(seq(-2, 2, 0.5), levels = seq(-2, 2, 0.5))) scale_color_manual(values = c("-2" = "#03254C", "-1.5" = "#1167B1", "-1" = "#187BCD", "-0.5" = "#2A9DF4", "0" = "white", "0.5" = "#FAD65F", "1" = "#F88E2A", "1.5" = "#FC6400", "2" = "#B72C0A"), breaks = seq(-2, 2, 0.5), limits = factor(seq(-2, 2, 0.5), levels = seq(-2, 2, 0.5))) facet_wrap(~cond1)

^{Created on 2021-12-08 by the}

alternatively:

ggplot(data=df, aes(x=cond2, y=animal, fill=FC_num, size=FC_num)) geom_point(pch = 21) scale_size_binned_area(max_size=10, breaks=breaks, labels=breaks) scale_fill_distiller(palette="RdBu", breaks=breaks, labels=breaks) guides(fill=guide_legend(reverse=TRUE), size = guide_legend(reverse=TRUE)) facet_wrap(~cond1)