regression_analysis_with_variables_in_the_same_column

library(readr)
library(dplyr)
library(tidyr)
library(ggplot2)

# data upload
github="https://raw.githubusercontent.com/agronomy4future/raw_data_practice/main/wheat_grain_Fe_uptake.csv"
dataA= data.frame(read_csv(url(github), show_col_types= FALSE))

# to adjust unbalanced data  
dataA_filtered= dataA %>%
  group_by(Location, Season, Genotype, Stage) %>%
  filter(n()>=20) %>%
  ungroup()

dummy_rows= dataA_filtered %>%
  complete(Location, Season, Genotype, Stage, 
           fill = list(Iron_ton_ha=NA, Fe=NA))

dataA_combined= bind_rows(dataA_filtered, dummy_rows)

# to transpose data structure
dataB= dataA_filtered %>%
  group_by(Location, Season, Genotype, Stage) %>%
  summarise(Iron_ton_ha=list(Iron_ton_ha), Fe=list(Fe)) %>%
  pivot_wider(names_from=Season, values_from=c(Iron_ton_ha, Fe), names_sep="_") %>%
  unnest(everything())

# to summarize data
dataC= data.frame(dataB %>%
                  group_by(Location, Genotype, Stage) %>%
                  dplyr::summarize(across(c(Fe_2021, Fe_2022), 
                                            .fns= list(Mean=mean, 
                                             SD= sd, 
                                             n=length,
                                             se=~ sd(.)/sqrt(length(.))))))

# to simplify data
dataC=dataC[, c("Location", "Genotype", "Stage", "Fe_2021_Mean",
                "Fe_2021_se", "Fe_2022_Mean", "Fe_2022_se")]

# to create a graph
FIGA=ggplot(data=subset(dataC, Stage=="Maturity"), aes(x=Fe_2021_Mean, y=Fe_2022_Mean)) +
  
  geom_errorbar(aes(xmin=Fe_2021_Mean-Fe_2021_se, xmax=Fe_2021_Mean+Fe_2021_se), 
                position=position_dodge(0.7),
                width=0.01) +
  geom_errorbar(aes(ymin=Fe_2022_Mean-Fe_2022_se, ymax=Fe_2022_Mean+Fe_2022_se), 
                position=position_dodge(0.7),
                width=0.01) +
  
  geom_point(aes(fill=Location, shape=Location), color= "black", size = 5) +
  geom_smooth(aes(group=Location),method='lm', linetype=1, se=FALSE, color="red", formula=y~x, size=0.5) +
  
  scale_fill_manual(values=c("tomato4","cadetblue")) +
  scale_shape_manual(values=c(21,21)) +
  scale_x_continuous(breaks=seq(0,0.25,0.05),limits=c(0,0.25)) +  
  scale_y_continuous(breaks=seq(0,0.1,0.02),limits=c(0,0.1)) +  
  labs(x="2021 season", y="2022 season") +
  theme_classic(base_size=18, base_family="serif") +
  theme(legend.position=c(0.8,0.15), 
        legend.title=element_blank(),
        legend.key=element_rect(color="white", fill="white"),
        legend.text=element_text(family="serif", face="plain",
                                 size=15, color="black"),
        legend.background= element_rect(fill="white"),
        strip.background=element_rect(color="white", 
                                      linewidth=0.5, linetype="solid"),
        axis.line = element_line(linewidth = 0.5, colour="black"))
FIGA+windows(width=5.5, height=5)