Penlight

• Index

Contents

• Functions

Libraries

• pl
• pl.Set
• pl.app
• pl.array2d
• pl.class
• pl.compat
• pl.comprehension
• pl.config
• pl.data
• pl.dir
• pl.file
• pl.func
• pl.import_into
• pl.input
• pl.lapp
• pl.lexer
• pl.luabalanced
• pl.operator
• pl.path
• pl.permute
• pl.pretty
• pl.seq
• pl.sip
• pl.strict
• pl.stringio
• pl.stringx
• pl.tablex
• pl.template
• pl.test
• pl.text
• pl.types
• pl.url
• pl.utils
• pl.xml

Classes

• pl.Date
• pl.List
• pl.Map
• pl.MultiMap
• pl.OrderedMap

Manual

• Introduction
• Tables and Arrays
• Strings. Higher-level operations on strings.
• Paths and Directories
• Date and Time
• Data
• Functional Programming
• Additional Libraries
• Technical Choices

Examples

• seesubst.lua
• sipscan.lua
• symbols.lua
• test-cmp.lua
• test-data.lua
• test-listcallbacks.lua
• test-pretty.lua
• test-symbols.lua
• testapp.lua
• testclone.lua
• testconfig.lua
• testglobal.lua
• testinputfields.lua
• testinputfields2.lua
• testxml.lua
• which.lua

Module pl.array2d

Operations on two-dimensional arrays.

See The Guide

Dependencies: pl.utils, pl.tablex, pl.types

Functions

size (t)	return the row and column size.
column (a, key)	extract a column from the 2D array.
map (f, a, arg)	map a function over a 2D array
reduce_rows (f, a)	reduce the rows using a function.
reduce_cols (f, a)	reduce the columns using a function.
reduce2 (opc, opr, a)	reduce a 2D array into a scalar, using two operations.
map2 (f, ad, bd, a, b, arg)	map a function over two arrays.
product (f, t1, t2)	cartesian product of two 1d arrays.
flatten (t)	flatten a 2D array.
reshape (t, nrows, co)	reshape a 2D array.
swap_rows (t, i1, i2)	swap two rows of an array.
swap_cols (t, j1, j2)	swap two columns of an array.
extract_rows (t, ridx)	extract the specified rows.
extract_cols (t, cidx)	extract the specified columns.
remove_row (t, i)	remove a row from an array.
remove_col (t, j)	remove a column from an array.
parse_range (s)	parse a spreadsheet range.
range (t, rstr)	get a slice of a 2D array using spreadsheet range notation.
slice (t, i1, j1, i2, j2)	get a slice of a 2D array.
set (t, value, i1, j1, i2, j2)	set a specified range of an array to a value.
write (t, f, fmt, i1, j1, i2, j2)	write a 2D array to a file.
forall (t, row_op, end_row_op, i1, j1, i2, j2)	perform an operation for all values in a 2D array.
move (dest, di, dj, src, i1, j1, i2, j2)	move a block from the destination to the source.
iter (a, indices, i1, j1, i2, j2)	iterate over all elements in a 2D array, with optional indices.
columns (a)	iterate over all columns.
new (rows, cols, val)	new array of specified dimensions

Functions

size (t)

return the row and column size.

Parameters:

• t array a 2d array

Returns:

1. int number of rows
2. int number of cols

column (a, key)

extract a column from the 2D array.

Parameters:

• a array 2d array
• key an index or key

Returns:

1d array

map (f, a, arg)

map a function over a 2D array

Parameters:

• f func a function of at least one argument
• a array 2d array
• arg an optional extra argument to be passed to the function.

Returns:

2d array

reduce_rows (f, a)

reduce the rows using a function.

Parameters:

• f func a binary function
• a array 2d array

Returns:

1d array

See also:

pl.tablex.reduce

reduce_cols (f, a)

reduce the columns using a function.

Parameters:

• f func a binary function
• a array 2d array

Returns:

1d array

See also:

pl.tablex.reduce

reduce2 (opc, opr, a)

reduce a 2D array into a scalar, using two operations.

Parameters:

• opc func operation to reduce the final result
• opr func operation to reduce the rows
• a 2D array

map2 (f, ad, bd, a, b, arg)

map a function over two arrays. They can be both or either 2D arrays

Parameters:

• f func function of at least two arguments
• ad int order of first array (1 or 2)
• bd int order of second array (1 or 2)
• a tab 1d or 2d array
• b tab 1d or 2d array
• arg optional extra argument to pass to function

Returns:

2D array, unless both arrays are 1D

product (f, t1, t2)

cartesian product of two 1d arrays.

Parameters:

• f func a function of 2 arguments
• t1 array a 1d table
• t2 array a 1d table

Returns:

2d table

Usage:

product('..',{1,2},{'a','b'}) == {{'1a','2a'},{'1b','2b'}}

flatten (t)

flatten a 2D array. (this goes over columns first.)

Parameters:

• t array 2d table

Returns:

a 1d table

Usage:

flatten {{1,2},{3,4},{5,6}} == {1,2,3,4,5,6}

reshape (t, nrows, co)

reshape a 2D array.

Parameters:

• t array 2d array
• nrows int new number of rows
• co bool column-order (Fortran-style) (default false)

Returns:

a new 2d array

swap_rows (t, i1, i2)

swap two rows of an array.

Parameters:

• t array a 2d array
• i1 int a row index
• i2 int a row index

swap_cols (t, j1, j2)

swap two columns of an array.

Parameters:

• t array a 2d array
• j1 int a column index
• j2 int a column index

extract_rows (t, ridx)

extract the specified rows.

Parameters:

• t array 2d array
• ridx {int} a table of row indices

extract_cols (t, cidx)

extract the specified columns.

Parameters:

• t array 2d array
• cidx {int} a table of column indices

remove_row (t, i)

remove a row from an array.

Parameters:

• t array a 2d array
• i int a row index

remove_col (t, j)

remove a column from an array.

Parameters:

• t array a 2d array
• j int a column index

parse_range (s)

parse a spreadsheet range. The range can be specified either as ‘A1:B2’ or ‘R1C1:R2C2’; a special case is a single element (e.g ‘A1’ or ‘R1C1’)

Parameters:

• s string a range.

Returns:

1. int start col
2. int start row
3. int end col
4. int end row

range (t, rstr)

get a slice of a 2D array using spreadsheet range notation. @see parse_range

Parameters:

• t array a 2D array
• rstr string range expression

Returns:

a slice

See also:

• array2d.parse_range
• array2d.slice

slice (t, i1, j1, i2, j2)

get a slice of a 2D array. Note that if the specified range has a 1D result, the rank of the result will be 1.

Parameters:

• t array a 2D array
• i1 int start row (default 1)
• j1 int start col (default 1)
• i2 int end row (default N)
• j2 int end col (default M)

Returns:

an array, 2D in general but 1D in special cases.

set (t, value, i1, j1, i2, j2)

set a specified range of an array to a value.

Parameters:

• t array a 2D array
• value the value (may be a function)
• i1 int start row (default 1)
• j1 int start col (default 1)
• i2 int end row (default N)
• j2 int end col (default M)

See also:

tablex.set

write (t, f, fmt, i1, j1, i2, j2)

write a 2D array to a file.

Parameters:

• t array a 2D array
• f a file object (default stdout)
• fmt string a format string (default is just to use tostring)
• i1 int start row (default 1)
• j1 int start col (default 1)
• i2 int end row (default N)
• j2 int end col (default M)

forall (t, row_op, end_row_op, i1, j1, i2, j2)

perform an operation for all values in a 2D array.

Parameters:

• t array 2D array
• row_op func function to call on each value
• end_row_op func function to call at end of each row
• i1 int start row (default 1)
• j1 int start col (default 1)
• i2 int end row (default N)
• j2 int end col (default M)

move (dest, di, dj, src, i1, j1, i2, j2)

move a block from the destination to the source.

Parameters:

• dest array a 2D array
• di int start row in dest
• dj int start col in dest
• src array a 2D array
• i1 int start row (default 1)
• j1 int start col (default 1)
• i2 int end row (default N)
• j2 int end col (default M)

iter (a, indices, i1, j1, i2, j2)

iterate over all elements in a 2D array, with optional indices.

Parameters:

• a array 2D array
• indices {int} with indices (default false)
• i1 int start row (default 1)
• j1 int start col (default 1)
• i2 int end row (default N)
• j2 int end col (default M)

Returns:

either value or i,j,value depending on indices

columns (a)

iterate over all columns.

Parameters:

• a array a 2D array

Returns:

each column in turn

new (rows, cols, val)

new array of specified dimensions

Parameters:

• rows int number of rows
• cols int number of cols
• val initial value; if it’s a function then use val(i,j)

Returns:

new 2d array