Lua Matrix Module

1. Overview

The matrix data structure module is globally registered and returned by the Lua require function.

2. Module

2.1. Example Usage

local matrix = require "streaming_algorithms.matrix"

local m = matrix.new(20, 10)
m:add(1, 1, 99)
m:add(20, 10, 100)
local val = m:get(1, 1)
-- val == 99

2.2. Functions

2.2.1. new

require "streaming_algorithms.matrix"
local m = streaming_algorithms.matrix.new(20, 10)

Arguments

• rows (unsigned) The number of rows in the matrix (must be > 1).
• cols (unsigned) The number of columns in the matrix (must be > 1).
• type (nil/string) int|float (default int)

Return

• matrix userdata object.

2.3. Methods

2.3.1. get_configuration

local rows, columns = m:get_configuration()

Returns the configuration of the matrix structure.

Arguments

• none - Return
• rows (unsigned) The number of rows in the matrix.
• columns (unsigned) The number of columns in the matrix.

2.3.2. add

v = m:add(1, 1, 1)
-- v == 1
v = m:add(1, 1, 99)
-- v == 100

Adds a value to the specified matrix cell.

Arguments

• row (unsigned)
• column (unsigned)
• value (number) The value to be added to the specified row/column.

Return

• The resulting value at the specified cell or nil if the request was out of bounds.

2.3.3. set

v = m:set(1, 1, 1)
-- v == 1
v = m:set(1, 1, 99)
-- v == 99

Overwrites the value at a specific cell.

Arguments

• row (unsigned)
• column (unsigned)
• value (number) The value to be overwritten at the specified row.

Return

• The value at the specified cell or nil if the request was out of bounds.

2.3.4. get

v = m:get(1, 1)
-- v == 99

Fetches the value at a specific cell.

Arguments

• row (unsigned)
• column (unsigned)

Return

• The value at the specified cell or nil if the request was out of bounds.

2.3.5. get_row

a = m:get_row(1)
-- a == {98, 99}

Returns an array of values containing column entries for the row.

Arguments

• row (unsigned)

Returns

• Array of values or nil if the request was out of bounds.

2.3.6. clear_row

m:clear_row(1)

Zeros out the specified row in the matrix.

Arguments

• row (unsigned)

Returns

• none

2.3.7. pcc

pcc, index = m:pcc(1)

Returns Pearson's correlation coefficient of the most similar/different row in the matrix.

Arguments

• row (unsigned)
• match (string) "max|min", default "max".

Returns

• pcc (number/nil) Pearson's correlation coefficient.
• index (int/nil) Row index of the best match.

2.3.8. merge

m:merge(m1, op)

Merges one matrix into another based on the specified operation.

Arguments

• m1 (userdata) Source matrix to merge.
• op (string/nil) One of the following entries:
  • add (default) - unlike the float add function NAN is ignored so merge will not clobber an initialized value in the destination matrix.
  • set

Return

• none

2.3.9. sum

sum = m:sum(10)
-- sum == 23

Returns the sum of the specified matrix row.

Arguments

• row (unsigned) Matrix row to compute the sum on (NAN is ignored).

Returns

• sum (number)

2.3.10. fromstring

m:fromstring(tostring(m1))

Restores a matrix to the previously serialized state.

Arguments

• serialization (string) The tostring output.

Return

• none or throws an error.