Hi, i'm quite new to R and need your help.

I have an excel sheet with measurements I have taken throughout several week. I have one measurement per week and would like to plot a line graph to visualize the development. In Excel i have one column for the exact date the measurements were taken and one with the numbers. The dates are in dd.mm.yyyy format and it seems like R recognizes it as dates.

Now, whenever i try to plot it the dates on the x-axis are not the ones i have in my excel sheet. When I change the dates into strings i get this comment:

geom_line()`: Each group consists of only one observation.

i Do you need to adjust the group aesthetic?

The graph now has the correct dates but it doesn't have any data in it.

When I try the data_df$Date <- as.Date(data_df$Date) it doesn't change anything, it shows the wrong dates still.

This is the code I've used so far:

library(ggplot2)

library(readxl)

# Read the Excel data

library(readxl)

Algae_analysis <- read_excel("Bachelorarbeit/Datenanalyse/Algae_analysis.xlsx",

sheet = "Spots", range = "A19:B27")

View(Algae_analysis)

# Convert Week column to string format

Algae_analysis$Week <- as.character(Algae_analysis$Week)

# Create a line plot

line_plot <- ggplot(Algae_analysis, aes(x = Week, y = `total conc.`

)) +

geom_line() +

labs(x = "Week", y = "Total Concentration") +

theme_minimal()

# Display the line plot

print(line_plot)

I would appreciate if anyone can help me out here as I need this for my thesis. Feel free to ask if anything is unclear.