In jbkunst/rchess: Chess Move, Generation/Validation, Piece Placement/ Movement, and Check/Checkmate/Stalemate Detection

# devtools::install_github("jbkunst/tufterhandout")
library("rchess")
options(digits = 3, knitr.table.format = "markdown")
knitr::opts_chunk$set(collapse = TRUE, warning = FALSE, fig.width = 5.5, fig.height = 5.5, dpi = 72)

Back to Top

Introduction

The rchess package is a chess move, generation/validation, piece placement/movement, and check/checkmate/stalemate detection.

Installation

Via standar install:

install.packages("rchess")

Or if you want to be risky you can install the latest development version from github with:

devtools::install_github("jbkunst/rchess")

Basic Usage

chss <- Chess$new()

Check the legal next moves:

chss$moves()

chss$moves(verbose = TRUE)

Make a move:

chss$move("a3")

We can concate some moves (and a captures)

chss$move("e5")$move("f4")$move("Qe7")$move("fxe5")

plot(chss)

Or a ggplot2 version (I know, I need to change the chess pieces symbols in unicode; maybe use a chess typeface)

plot(chss, type = "ggplot")

There are function to get information of actual position:

chss$turn()

chss$square_color("h1")

chss$get("e5")

chss$history(verbose = TRUE)

chss$history()

chss$undo()

chss$history()

chss$fen()

You can edit the header.

chss$header("White", "You")
chss$header("WhiteElo", 1800)
chss$header("Black", "Me")
chss$header("Date", Sys.Date())
chss$header("Site", "This R session")

Get the header

chss$get_header()

And get the pgn.

cat(chss$pgn())

Or plot the board in ascii format:

chss$ascii()

Load PGN and FEN

FEN

chssfen <- Chess$new()

fen <- "rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq c6 0 2"

chssfen$load(fen)

plot(chssfen)

PGN

pgn <- system.file("extdata/pgn/kasparov_vs_topalov.pgn", package = "rchess")
pgn <- readLines(pgn, warn = FALSE)
pgn <- paste(pgn, collapse = "\n")
cat(pgn)

chsspgn <- Chess$new()

chsspgn$load_pgn(pgn)

cat(chsspgn$pgn())

chsspgn$history()

chsspgn$history(verbose = TRUE)

plot(chsspgn)

Validation Functions

State validation

chss2 <- Chess$new("rnb1kbnr/pppp1ppp/8/4p3/5PPq/8/PPPPP2P/RNBQKBNR w KQkq - 1 3")

plot(chss2)

chss2$in_check()

chss2$in_checkmate()

Slatemate validation

chss3 <- Chess$new("4k3/4P3/4K3/8/8/8/8/8 b - - 0 78")

plot(chss3)

chss3$in_stalemate()

Three fold repetition

chss4 <- Chess$new("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")

chss4$in_threefold_repetition()

chss4$move('Nf3')$move('Nf6')$move('Ng1')$move('Ng8')

chss4$in_threefold_repetition()

chss4$move('Nf3')$move('Nf6')$move('Ng1')$move('Ng8')

chss4$in_threefold_repetition()

chss4$history()

Insufficient material

chss5 <- Chess$new("k7/8/n7/8/8/8/8/7K b - - 0 1")

plot(chss5)

chss5$insufficient_material()

Helpers Functions

There some helper function to get more information

History Detail

This functions is a detailed version from the history(verbose = TRUE).

chsspgn$history_detail()

Plot a board via ggplot

You can plot a specific fen vía ggplot:

ggchessboard(chsspgn$fen())

Auxiliar Data

There function to retrieve some data which is easier to plot:

Pieces

rchess:::.chesspiecedata()

Board

rchess:::.chessboarddata()

Data

The package have two data sets:

FIDE World cups

data("chesswc")
str(chesswc)
head(chesswc)

Chess Openings

data("chessopenings")
str(chessopenings)
head(chessopenings)

More Details

Under the hood

This package is mainly a wrapper of chessjs by jhlywa.

The main parts in this package are:

• V8 package and chessjs javascript library.
• R6 package for the OO system.
• htmlwidget package and chessboardjs javascript library.

Thanks to the creators and maintainers of these packages and libraries.

Session Info

print(sessionInfo())

jbkunst/rchess documentation built on May 18, 2019, 7 p.m.