There are three plot[X].R files in this repository, for X in (1,2,3) Each R file contains one function plot[X]. When called, each function produces one plot[X].png in the working directory, as defined in the assignment (https://github.com/rdpeng/ExData_Plotting1)
Please make sure that there is a text file "household_power_consumption.txt" in the working directory with the contents of the zip file https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip.
Each function starts by loading and slicing the data, and there is no test for the presence of the file (considered out of scope of the project).