plot2.R

library(lubridate)
library(dplyr)
Sys.setlocale("LC_TIME", "en_US.UTF-8")

#txt_data<-read.table(file = "./household_power_consumption.txt",strip.white = T,sep = ";",header=T)

# Convert the variable "Date" into date.
#txt_data$Date<-dmy(txt_data$Date)
#txt_data$Time<-hms(txt_data$Time)

# Select two specific days : 01 and 02 february 2007
txt_data_trunced<-txt_data[txt_data$Date>="2007-02-01" & txt_data$Date<="2007-02-02",]

# Mutate then delete variables Date and Time into new variable named new.date
txt_data_trunced %<>% mutate(new.date=Date+Time,Date=NULL,Time=NULL)
txt_data_trunced %<>% relocate(new.date)


# Convert variables into numerics
txt_data_trunced[,2:8]<-txt_data_trunced %>% summarise(across(Global_active_power:Sub_metering_3,as.numeric),.groups = "keep")

# Open a png file, store it the histogram and close the file
png(file="plot2.png",
    width=480, height=480)
plot(txt_data_trunced[,1],txt_data_trunced[,2],type="s",xlab = "",ylab = "Global Active Power (kilowatts)")
dev.off()