Average variables and create line graph

[Mui_Nguyen]

Hello everyone,

I'm very new in R using and trying to explore about this software.I am seeking the advice that how can I average the data based on variable then draw line graphs?
For example, I have a data frame named mydata like this:
Cultivar Period Height
Cultivar A 1 32
Cultivar A 1 23
Cultivar B 1 34
Cultivar B 1 43
Cultivar C 1 43
Cultivar C 1 43
Cultivar A 2 24
Cultivar A 2 43
Cultivar B 2 32
Cultivar B 2 23
Cultivar C 2 33
Cultivar C 2 34
Cultivar A 3 23
Cultivar A 3 33
Cultivar B 3 44
Cultivar B 3 32
Cultivar C 3 42
Cultivar C 3 42
I want to draw the line graph in which x-axis presented by "Period"(3 periods), y-axis is "plant height" and the graph is filled by Cultivar.
I have tried this coding:
data<-mydata %>% group_by(Cultivar) %>% summarize(averaged.ES=mean(Height), sd.ES=sd(Height))
Because I want to average the data based on Cultivar first, but the graph was showing sawtooth pattern.
Your advice would be very appreciated!

Thank you very much!

[andresrcs]

Hi, welcome!

Is this what you are trying to do?

# Library calls
library(tidyverse)

# Sample data on a copy/paste friendly format
mydata <- data.frame(
  stringsAsFactors = FALSE,
          Cultivar = c("A","A","B","B","C","C",
                       "A","A","B","B","C","C","A","A","B","B","C","C"),
            Period = c(1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3),
            Height = c(32,23,34,43,43,43,24,43,
                       32,23,33,34,23,33,44,32,42,42)
)

# Relevant code
mydata %>% 
    group_by(Period,Cultivar) %>% 
    summarise(mean_heigh = mean(Height, na.rm = TRUE)) %>% 
    ggplot(aes(x = Period, y = mean_heigh, color = Cultivar)) +
    geom_line()

^{Created on 2020-02-13 by the reprex package (v0.3.0.9001)}

If this doesn't solve your problem, please provide a proper REPRoducible EXample (reprex) illustrating your issue.

[Mui_Nguyen]

Thank you so much Andresrcs,

I got your idea!