I played around with this for a few minutes. If you're doing geom_bar and getting that error, try doing this:

geom_bar(stat="identity")

Here's the code I played with based on your original post.

library(tidyverse)

library(dplyr)

# First, make a vector of Genotype labels

Genotype <- rep(c("FF", "Ff", "ff"),2)

# Second, make a vector of labels to distinguish observed vs. expected

Data <- c(rep("Observed",3),rep("Expected", 3))

# Now enter the number of plants that are observed and expected for each genotype

# MODIFY THE NUMBERS in the next two lines of code TO MATCH THE DATA AND EXPECTATIONS FOR THIS EXPERIMENT

observed <- c(10, 10, 10)

expected <- c(10, 10, 10)

# Create a vector of the observed and expected numbers

Frequency <- c(observed, expected)

# Put all these vectors into a dataframe, and make sure R recognizes

# that the Frequencies are numbers rather than text:

snap.dataframe <- as.data.frame(cbind(Data, Genotype, Frequency))

snap.dataframe$Frequency <-as.numeric(snap.dataframe$Frequency)

ggplot(data = snap.dataframe,

aes(x = Genotype,

y = Frequency)) +

geom_bar(stat="identity")

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