[R] barplot_add=TRUE

[Sibylle Stöckli]

Dear R users

aim
Barplot of insect trap catches (y variable trapcatch) at one specific station (variable FiBL_Hecke) from week 1-52 ( x variable week).
It works well using the function tapply (sum trapcatch per week, males and females not separated), however, I intend to separate the y variable trapcatch in males and females (variable m_w: m and w)

problem
I used the function "add" to merge two bar plots (males and females). Unfortunately the second barplot masks the first barplot.

question
Is there a function to "mathematically" add the values from both barplots with the aim the barplot presenting the total trap (males and females) catches per week?



Hecke<-trap[trap$station=="FiBL_Hecke",] # station = Hecke
m<-Hecke[Hecke$m_w=="m",] # male trap catches
w<-Hecke[Hecke$m_w=="w",] # female trap catches

barplot(m$trapcatch, ylab="Y", space=0.5, col=c("grey0"), ylim=c(0,450), las=2, cex.lab=0.9, cex.axis=0.9, cex.names=0.9)
barplot(w$trapcatch,space=0.5, add=TRUE, beside=FALSE, col=c("grey50"), xaxt="n", yaxt="n")

Thanks a lot
Sibylle
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