Trouble with bar plot 2 categorical variable x axis

[Ina]

Famíly	Moon	Resíduo
Epinephelidae	crescente	52.893
Epinephelidae	cheia	47.021
Epinephelidae	minguante	0.043
Epinephelidae	nova	0.043
Lutjanidae	crescente	-1.248
Lutjanidae	cheia	2.635
Lutjanidae	minguante	-0.139
Lutjanidae	nova	-1.248

I want to plot like this:

[cderv]

hi,

what did you try so far ?

[Ina]

resfam<-read.csv("residuo-barplot.csv", sep = ";")
resfam
resfami<-ggplot(resfam, aes(x = Lua, y = Resíduo, fill = Família)) + geom_bar(position="identity", stat = "identity", width = 0.5) + theme_classic()
resfami

but i would like 2 bars representing the families in the x axis instead of using "fill" to separate them.

[cderv]

@Ina

i would like 2 bars representing the families in the x axis instead of using "fill" to separate them.

You are looking for the group aesthetic and you need to use position dodge to put bar next to another.

Look at documentation for example of position_dodge()

Bar charts — geom_bar

one possible answer if you don't want to try yourself

tab <- tibble::tribble(
          ~Family,       ~Moon, ~Residuo,
  "Epinephelidae", "crescente",   52.893,
  "Epinephelidae",     "cheia",   47.021,
  "Epinephelidae", "minguante",    0.043,
  "Epinephelidae",      "nova",    0.043,
     "Lutjanidae", "crescente",   -1.248,
     "Lutjanidae",     "cheia",    2.635,
     "Lutjanidae", "minguante",   -0.139,
     "Lutjanidae",      "nova",   -1.248
  )

library(ggplot2)
ggplot(tab, aes(x = Moon, y = Residuo)) + 
  geom_col(aes(group = Family), position = "dodge", fill = "lightblue") +
  theme_classic()

^{Created on 2019-01-25 by the reprex package (v0.2.1)}