Converting a hist() and boxplot() object into a ggplot() object to align my plots using plot_grid() in the Cowplot Package in R

Question

I am checking my data for normality and I have created boxplots - boxplot() , histograms - hist() , and ggqqplots() (using the ggpubr package, which is aligned with ggplot ). The data shows measurements of acoustic parameters within spectrograms using Raven Software.

For this project, I need to visually represent my results neatly and I want to use plot_grid() in the cowplot Package to align my plots in 9 columns and 3 rows. I have produced 9 boxplots, 9 histograms, and 9 ggqqplot() objects.

When I attempted to align my plots using the plot_grid() function, the qqggplot() printed but the hist() and boxplots() objects did not (see diagram 1) . I learned that I need to convert my hist() and boxplot() objects into grob objects.

I found a website (below) that stated could use as.glob() or as.ggplot() to convert my diagrams. I used the information from this link below, although, unsuccessfully.

Conversion to grob objects

After I attempted to convert my hist() and boxplot() objects to grob object (so they will analogously be ggplot objects for the plot_grid() command) using the as.grob() function, I got error message 2 (see below).

R Code

#Install library packages
library("ggpubr")
library("grid")
library("ggplotify")
library(ggplot2)
library(cowplot)

#Box plots
Low_Freq_Box<-boxplot(main_path$Low.Freq..Hz.)
High_Freq_Box<-boxplot(main_path$High.Freq..Hz.)
Peak_Freq_Box<-boxplot(main_path$Peak.Freq..Hz.)
Delta_Freq_Box<-boxplot(main_path$Delta.Freq..Hz.)
Peak_Time_Box<-boxplot(main_path$ Peak.Time..s.)
Delta_Time_Box<-boxplot(main_path$Delta.Time..s.)
Center_Freq_Box<-boxplot(main_path$Center.Freq..Hz.)
Start_Freq_Box<-boxplot(main_path$Start.Freq..Hz.)
End_Freq_Box<-boxplot(main_path$End.Freq..Hz.)

#Histograms
Low_Freq_hist<-hist(main_path$Low.Freq..Hz.)
High_Freq_hist<-hist(main_path$High.Freq..Hz.)
Peak_Freq_hist<-hist(main_path$Peak.Freq..Hz.)
Delta_Freq_hist<-hist(main_path$Delta.Freq..Hz.)
Peak_Time_hist<-hist(main_path$Peak.Time..s.)
Delta_Time_hist<-hist(main_path$Delta.Time..s.)
Center_Freq_hist<-hist(main_path$Center.Freq..Hz.)
Start_Freq_hist<-hist(main_path$Start.Freq..Hz.)
End_Freq_hist<-hist(main_path$End.Freq..Hz.)

#QQ Plots
Low_Freq_qqplot<-ggqqplot(main_path$Low.Freq..Hz.)
High_Freq_qqplot<-ggqqplot(main_path$High.Freq..Hz.)
Peak_Freq_qqplot<-ggqqplot(main_path$Peak.Freq..Hz.)      
Delta_Freq_qqplot<-ggqqplot(main_path$Delta.Freq..Hz.)   
Delta_Time_qqplot<-ggqqplot(main_path$Delta.Time..s.)    
Peak_Time_qqplot<-ggqqplot(main_path$Peak.Time..s.)    
Center_Freq_qqplot<-ggqqplot(main_path$Center.Freq..Hz.)    
Start_Freq_qqplot<-ggqqplot(main_path$Start.Freq..Hz.)    
End_Freq_qqplot<-ggqqplot(main_path$End.Freq..Hz.)    

Error Message 1

#Plot the box plots, histograms, and qqplots on the same grid
plot_grid(Low_Freq_Box, High_Freq_Box, Peak_Freq_Box, Delta_Freq_Box, Peak_Time_Box, Delta_Time_Box, Center_Freq_Box, Start_Freq_Box, End_Freq_Box,
          Low_Freq_hist, High_Freq_hist, Peak_Freq_hist, Delta_Freq_hist, Peak_Time_hist, Delta_Time_hist, Center_Freq_hist, Start_Freq_hist, End_Freq_hist, 
          Low_Freq_qqplot, High_Freq_qqplot, Peak_Freq_qqplot, Delta_Freq_qqplot, Delta_Time_qqplot, Peak_Time_qqplot, Center_Freq_qqplot, Start_Freq_qqplot, End_Freq_qqplot,
          labels=c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14', 15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27"),
          ncol=9, nrow=3)

    #Warning Messages
plot_grid(Low_Freq_Box, High_Freq_Box, Peak_Freq_Box, Delta_Freq_Box, Peak_Time_Box, Delta_Time_Box, Center_Freq_Box, Start_Freq_Box, End_Freq_Box,
+           Low_Freq_hist, High_Freq_hist, Peak_Freq_hist, Delta_Freq_hist, Peak_Time_hist, Delta_Time_hist, Center_Freq_hist, Start_Freq_hist, End_Freq_hist, 
+           Low_Freq_qqplot, High_Freq_qqplot, Peak_Freq_qqplot, Delta_Freq_qqplot, Delta_Time_qqplot, Peak_Time_qqplot, Center_Freq_qqplot, Start_Freq_qqplot, End_Freq_qqplot,
+           labels=c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27"),
+           ncol=9, nrow=3,
+           align="hv",
+           label_size = 12)
There were 20 warnings (use warnings() to see them)

Diagram 1

Answer 1

Answer:

To convert base objects such as hist() and boxplot() into ggplot objects to arrange using the plot_grid() function, you can use the function as.ggplot().

#Box plots
Low_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Low.Freq))
High_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$High.Freq))
Peak_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Peak.Freq))
Delta_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Delta.Freq))
Peak_Time_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Peak.Time))
Delta_Time_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Delta.Time))
Center_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Center.Freq))
Start_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$Start.Freq))
End_Freq_Box<-as.ggplot(~boxplot(New_Acoustic_Parameters$End.Freq))

#Histograms
Low_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Low.Freq))
High_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$High.Freq))
Peak_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Peak.Freq))
Delta_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Delta.Freq))
Peak_Time_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Peak.Time))
Delta_Time_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Delta.Time))
Center_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Center.Freq))
Start_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$Start.Freq))
End_Freq_hist<-as.ggplot(~hist(New_Acoustic_Parameters$End.Freq))

#QQ Plots
Low_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$Low.Freq)
High_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$High.Freq)
Peak_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$Peak.Freq)      
Delta_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$Delta.Freq)   
Delta_Time_qqplot<-ggqqplot(New_Acoustic_Parameters$Peak.Time)    
Peak_Time_qqplot<-ggqqplot(New_Acoustic_Parameters$Delta.Time)    
Center_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$Center.Freq)    
Start_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$Start.Freq)    
End_Freq_qqplot<-ggqqplot(New_Acoustic_Parameters$End.Freq)    

#Open a new graphics window
dev.new()

#Plot the box plots, histograms, and qqplots on the same grid
plot_grid(Low_Freq_Box, High_Freq_Box, Peak_Freq_Box, Delta_Freq_Box, Peak_Time_Box, Delta_Time_Box, Center_Freq_Box, Start_Freq_Box, End_Freq_Box,
          Low_Freq_hist, High_Freq_hist, Peak_Freq_hist, Delta_Freq_hist, Peak_Time_hist, Delta_Time_hist, Center_Freq_hist, Start_Freq_hist, End_Freq_hist, 
          Low_Freq_qqplot, High_Freq_qqplot, Peak_Freq_qqplot, Delta_Freq_qqplot, Delta_Time_qqplot, Peak_Time_qqplot, Center_Freq_qqplot, Start_Freq_qqplot, End_Freq_qqplot,
          labels=c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27"),
          ncol=9, nrow=3,
          align="hv",
          label_size = 9,
          axis = "tblr")

Diagram:

Answer 2

Have you tried using the grid.arrange() function of the gridExtra package?

There is an example on Cran here

For you it would look like this

library(gridExtra)
library(grid)
library(ggplot2)

grid.arrange(Low_Freq_Box, High_Freq_Box, Peak_Freq_Box, Delta_Freq_Box, Peak_Time_Box, Delta_Time_Box, Center_Freq_Box, Start_Freq_Box, End_Freq_Box,
          Low_Freq_hist, High_Freq_hist, Peak_Freq_hist, Delta_Freq_hist, Peak_Time_hist, Delta_Time_hist, Center_Freq_hist, Start_Freq_hist, End_Freq_hist, 
          Low_Freq_qqplot, High_Freq_qqplot, Peak_Freq_qqplot, Delta_Freq_qqplot, Delta_Time_qqplot, Peak_Time_qqplot, Center_Freq_qqplot, Start_Freq_qqplot, End_Freq_qqplot)