Plot multiple variables on same Barplot in R - r

Question

I would really appreciate some help with this plot. I'm very new to R and struggling (after looking at many tutorials!)to understand how to plot the following:
This is my Table
The X axis is meant to have PatientID, the Y is cell counts for each patient
I've managed to do a basic plot for each variable individually, eg:
This is for 2 of the variables
And this gives me 2 separate graphs
Total cell counts
Cells counts for zone 1
I would like all the data represented on 1 graph...That means for each patient, there will be 4 bars (tot cell counts, and cell counts for each zone (1 - 3).
I don't understand whether I should be doing this as a combined plot or make the 4 different plots and then combine them together? I'm also very confused with how to actually code this. I've tried ggplot and I've done the regular Barplot in R (worked for 1 variable at a time but not sure how to do many variables). Some very step-by-step help would be so much appreciated here. TIA

Answer 1

Here's a way of doing it using the ggplot2 and tidyr packages from the tidyverse. The key steps are pivoting your data from "wide" to "long" format in order to make it usable with ggplot2. Afterwards, the ggplot call is pretty simple - more info here if you want a bit more explanation about stacked and bar plots in ggplot2, with an example that's pretty much identical to yours.
library(ggplot2)
library(tidyr)
# Reproducing your data
dat <- tibble(
patientID = c("a", "b", "c"),
tot_cells = c(2773, 3348, 4023),
tot_cells_zone1 = c(994, 1075, 1446),
tot_cells_zone2 = c(1141, 1254, 1349),
tot_cells_zone3 = c(961, 1075, 1426)
)
to_plot <- pivot_longer(dat, cols = starts_with("tot"), names_to = "Zone", values_to = "Count")
ggplot(to_plot, aes(x = patientID, y = Count, fill = Zone)) +
geom_bar(position="dodge", stat="identity")
Output:

Answer 2

Thanks everyone for your help. I was able to make the plot as follows:
First, I made a new table from data I imported into R:
#Make new table of patientID and tot cell count
patientID <- c("a", "b", "c")
tot_cells <- c(tot_cells_a, tot_cells_b, tot_cells_c)
tot_cells_zone1 <- c(tot_cells_a_zone1, tot_cells_b_zone1, tot_cells_c_zone1)
tot_cells_zone2 <- c(tot_cells_a_zone2, tot_cells_b_zone2, tot_cells_c_zone2)
tot_cells_zone3 <- c(tot_cells_a_zone3, tot_cells_b_zone3, tot_cells_c_zone3)
tot_cells_table <- data.frame(tot_cells,
tot_cells_zone1,
tot_cells_zone2,
tot_cells_zone3)
rownames(tot_cells_table) <- c(patientID)
Then I plotted as such, first converting the data.frame to matrix :
#Plot "Total Microglia Counts per Patient"
tot_cells_matrix <- data.matrix(tot_cells_table, rownames.force = patientID)
par(mar = c(5, 4, 4, 10),
xpd = TRUE)
barplot(t(tot_cells_table[1:3, 1:4]),
col = c("red", "blue", "green", "magenta"),
main = "Total Microglia Counts per Patient",
xlab = "Patient ID", ylab = "Cell #",
beside = TRUE)
legend("topright", inset = c(- 0.4, 0),
legend = c("tot_cells", "tot_cells_zone1",
"tot_cells_zone2", "tot_cells_zone3"),
fill = c("red", "blue", "green", "magenta"))
And the graph looks like this:
Barplot of multiple variables
Thanks again for pointing me in the right direction!