Package cs2110

Class Gradebook

java.lang.Object

cs2110.Gradebook

public class Gradebook
extends Object

A collection of static methods for reading/writing gradebook tables in CSV format, transforming their data, and calculating summary statistics.

Constructor Summary

Constructors

Constructor	Description
Gradebook()

Method Summary

Modifier and Type	Method	Description
static void	addSummaryColumns(Seq<Seq<String>> table)	Append "mean" and "standard deviation" columns to the end of the table `table`.
static void	addSummaryRows(Seq<Seq<String>> table)	Append "mean" and "standard deviation" rows to the bottom of the table `table`.
static Seq<Seq<String>>	constructTable(String filename)	Read contents of a csv file and use this to construct a nested row-major sequence of strings.
private static <T> boolean	isRectangular(Seq<Seq<T>> table)	Return whether each element of `table` has the same size.
static void	main(String[] args)	A basic application to add summary statistics to a gradebook spreadsheet table.
static double	mean(Seq<String> seq)	Return the mean of the numerical entries of `seq`.
static <T> void	outputCSV(String filename, Seq<Seq<T>> table)	Convert the contents of `table` into Simplified CSV format and write this to the file located at `filename`.
static double	powerSum(Seq<String> seq, int n)	Return the sum of the n'th powers of all numerical entries of `seq`.
static Seq<Seq<String>>	roundEntries(Seq<Seq<String>> table, int decimalPlaces)	Rounds all numerical data within `table` to the specified number of decimal places.
static double	stdDev(Seq<String> seq)	Return the standard deviation of the numerical entries of `seq`.
static <T> Seq<Seq<T>>	transpose(Seq<Seq<T>> original)	Return a new table that is the transpose of the original table.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Gradebook

public Gradebook()

Method Details

constructTable

public static Seq<Seq<String>> constructTable(String filename)
                                       throws IOException

Read contents of a csv file and use this to construct a nested row-major sequence of strings. Throws an IOException if `filename` cannot be accessed or read from.

Throws:

IOException

outputCSV

public static <T> void outputCSV(String filename,
 Seq<Seq<T>> table)
                          throws IOException

Convert the contents of `table` into Simplified CSV format and write this to the file located at `filename`. Throws an IOException if `filename` cannot be accessed or written to.

Throws:

IOException

isRectangular

private static <T> boolean isRectangular(Seq<Seq<T>> table)

Return whether each element of `table` has the same size.

transpose

public static <T> Seq<Seq<T>> transpose(Seq<Seq<T>> original)

Return a new table that is the transpose of the original table. That is, the rows of the original table become the columns of the new table (and vice versa), and the orders of the entries in these rows / columns remains the same. Requires `original` is rectangular.

powerSum

public static double powerSum(Seq<String> seq,
 int n)

Return the sum of the n'th powers of all numerical entries of `seq`. A numerical entry is any entry that can be successfully parsed to a double by Double.parseDouble().

mean

public static double mean(Seq<String> seq)

Return the mean of the numerical entries of `seq`. Returns NaN (aka 0.0/0.0) if `seq` does not contain any numerical entries.

stdDev

public static double stdDev(Seq<String> seq)

Return the standard deviation of the numerical entries of `seq`. Returns NaN (aka 0.0/0.0) if `seq` does not contain any numerical entries.

addSummaryColumns

public static void addSummaryColumns(Seq<Seq<String>> table)

Append "mean" and "standard deviation" columns to the end of the table `table`. The first row of the table (the column "headers") has "mean" and "standard deviation" appended (in that order). In subsequent rows, the string representations of the mean and standard deviation (in that order) of the numerical entries are appended. All numbers are represented with full precision. Requires that `table` is rectangular with at least one row and that no rows alias one another.

addSummaryRows

public static void addSummaryRows(Seq<Seq<String>> table)

Append "mean" and "standard deviation" rows to the bottom of the table `table`. The first entries of these rows are "mean" and "standard deviation" (respectively). The subsequent entries are the mean and standard deviation (respectively) of the numerical entries in that column. All numbers are represented with full precision. Requires that `table` is rectangular with at least one column (implying at least one row).

roundEntries

public static Seq<Seq<String>> roundEntries(Seq<Seq<String>> table,
 int decimalPlaces)

Rounds all numerical data within `table` to the specified number of decimal places.

main

public static void main(String[] args)
                 throws IOException

A basic application to add summary statistics to a gradebook spreadsheet table. Takes in two program arguments: the filepath of the input csv and the filepath for the output csv.

Throws:

IOException