Overlay two scatter plots into just one (with ggplot)

Question

Overlay two scatter plots into just one (with ggplot)

I have 2 data frames one for males and one for females (the variables are the same, crc and maxilla). From each of these df I generated two graphs. Now I'm trying to combine them into just one chart, but as they have number of different lines I can't do it.

The DFS are as follows:

alometria_M_max = (data.frame(crc_M, maxilla_M))

      crc_M maxilla_M
1  5.897154  1.398717
2  6.102559  1.560248
3  6.173786  1.640937
4  6.001415  1.515127
5  5.926926  1.388791
6  5.926926  1.458615
7  5.863631  1.558145
8  5.960232  1.528228
9  5.880533  1.437463
10 6.082219  1.547563
11 5.973810  1.521699
12 5.918894  1.458615
13 5.855072  1.423108
14 5.808142  1.283708

alometria_F_max = (data.frame(crc_F, maxilla_F))

      crc_F maxilla_F
1  6.198479  1.576915
2  6.295266  1.701105
3  6.418365  1.884035
4  6.393591  1.818077
5  6.120297  1.665818
6  6.142037  1.633154
7  6.139885  1.615420
8  5.855072  1.543298
9  5.913503  1.665818
10 6.165418  1.479329
11 6.107023  1.607436
12 6.214608  1.710188
13 6.171701  1.684545

Charts

plot_M <- ggplot(alometria_M_max, aes(x=crc_M, y= maxilla_M)) + 
  geom_point(color="green") + 
  theme_bw() + 
  theme_classic() + 
  geom_smooth(method = "lm", se= FALSE, color= "green")

plot_F <- ggplot(alometria_F_max, aes(x=crc_F, y= maxilla_F)) + 
  geom_point(color="red") + 
  theme_bw() + 
  theme_classic() + 
  geom_smooth(method = "lm", se= FALSE, color= "red")

Anyone, please, have any idea how do I put these two graphs together into just one, with the slope lines of the regression visible?

4

r ggplot2 gráfico-de-dispersão

Author: Marcus Nunes, 2020-11-04

Source

1 answers

score 5 · Accepted Answer

Like almost everything in ggplot2, the best way to solve graph display problems is by organizing the data frame. In case, I suggest it be a data frame only, with three columns: crc, maxilla and grupo. The group column will indicate which crc and maxilla belong to each group, in case M or F.

Below I show how my solution turned out:

crc_M <- c(5.897154, 6.102559, 6.173786, 6.001415, 
  5.926926, 5.926926, 5.863631, 5.960232, 
  5.880533, 6.082219, 5.973810, 5.918894, 
  5.855072, 5.808142)

maxilla_M <- c(1.398717, 1.560248, 1.640937, 1.515127, 
  1.388791, 1.458615, 1.558145, 1.528228, 
  1.437463, 1.547563, 1.521699, 1.458615, 
  1.423108, 1.283708)

crc_F <- c(6.198479, 6.295266, 6.418365, 6.393591,
           6.120297, 6.142037, 6.139885, 5.855072, 
           5.913503, 6.165418, 6.107023, 6.214608, 
           6.171701)

maxilla_F <- c(1.576915, 1.701105, 1.884035, 1.818077, 
               1.665818, 1.633154, 1.615420, 1.543298, 
               1.665818, 1.479329, 1.607436, 1.710188, 
               1.684545)

alometria <- data.frame(crc = c(crc_M, crc_F),
                        maxilla = c(maxilla_M, maxilla_F),
                        grupo = rep(c("M", "F"), 
                                    c(length(crc_M), length(crc_F))))

library(ggplot2)

ggplot(alometria, aes(x = crc, y = maxilla, colour = grupo, group = grupo)) +
  geom_point() +
  geom_smooth(aes(colour = grupo), method = "lm", se = FALSE)
#> `geom_smooth()` using formula 'y ~ x'

^{Created on 2020-11-04 by the reprex package (v0.3.0)}