plot1.R

Plot 1: Histogram of Global Active Power

Read data

data <- read.table( "household_power_consumption.txt", header = TRUE, sep = ";", na.strings = "?", stringsAsFactors = FALSE )

Subset data for the required dates

data <- subset( data, Date == "1/2/2007" | Date == "2/2/2007" )

Convert Global_active_power to numeric

data$Global_active_power <- as.numeric(data$Global_active_power)

Create PNG file

png("plot1.png", width = 480, height = 480)

Plot histogram

hist( data$Global_active_power, col = "red", main = "Global Active Power", xlab = "Global Active Power (kilowatts)" )

Close device

dev.off()