A matrix in the context of this code module is a python list whose elements are made up of a number of other lists which are uniform in terms of their element count. This list-of-lists structure thus forms a two-dimensional grid, a matrix, filled with individual cells.
5x5 spiral matrix
A spiral matrix is a particular type of squared-shaped matrix where each cell is populated with one value from a series of elements. The 'spiral' in 'spiral matrix' refers to the condition that each cell is progressively populated with a value from the series following a pattern that conforms to a tightly-wound spiral. This spiral progression begins from the center cell, moving outward. Ultimately, the entire matrix is populated with elements from the series.
5x5 including command-line
The remainder of this document details the practical application of executing spiral-matrix from the command-line. For an explanation of api usage when importing as a Python 3.x module, please click here.
DIMENSION
This parameter is an integer value, and is limited
to odd numbers only. This count of rows and columns
constitute the constructed size of the the square-
shaped 2-d matrix. (REQUIRED)
Column and row axis-labels along the top- and left-side can be prefixed to the printed output. Proceeding outward from the center cell in one compass direction or bearing, i.e East, North, West, or South, initiates the progression of the spiral. The spiral can be configured to progress in either a clockwise or counter-clockwise manner.
7x7 with axes, bearing: south, center: 1000, step: -300
--axes
This parameter-less option enables or disables the
prefixing of column- and row-axes labels along the
top- and left-side of the printed output.
(default: False)
--bearing EAST | NORTH | WEST | SOUTH
This compass bearing (E, N, W, or S) specifies
the direction that is used to proceed initially
outward from the center of the matrix.
(default: E)
--right
This parameter-less option generates a spiral
which progresses in a clockwise manner. Not for use
with 'left'. (default: not used)
--left
This parameter-less option generates a spiral
which progresses in a counter-clockwise manner,
which is the default behavior. Not for use with
'right'. Included for completeness.
The default style for the generated matrix consists of the series of integers that begin with '1' and then increments by '1' for each element of the series. Either of these integer values may be modified in order to change the generated matrix’s cell contents. Any positive or negative integer, or zero, is acceptable to occupy the center cell that starts the spiral. The increment integer must be a positive or negative, non-zero integer.
Use of the following options will modify the implementation of the default behavior.
--center INTEGER
This integer value is used to populate the center
cell that begins the spiral. (default: 1)
--step INTEGER
This integer value is used to increment the next
cell's value as the spiral progresses from cell to
cell. (default: 1)
As an alternative to populating the cells with a series of incrementing integers, a string of whitespace-delimited text elements, or word tokens, can be supplied. This string of tokens might consist of any combination of words, numbers, punctuation, or whitespace. The token string can be read from a file or stdin, or provided via command-line parameter.
5x5 with axes, bearing: south, series: lorem_ipsum
Use of either of the following options will replace the default behavior of populating the cells with a series of incrementing integers.
--file FILENAME
The specified file should contain some amount of
whitespace-delimited text elements. The cells of
the matrix are then populated using these elements.
Usage of the 'words' option is excluded when using
this option. (default: not used)
--words [STRING]
This string of whitespace-delimited text elements
is used to populate the cells of the matrix. When
this option is present with no string parameter
given, then string is read from stdin. When
utilizing stdin for string input, this option needs
to be the last option provided on the command-line.
Usage of the 'file' option is excluded when using
this option. (default: not used)
9x9, spiral: right, series: stormy_night
pypi: https://pypi.python.org/pypi/spiral-matrix
code repo: https://github.com/zero2cx/spiral-matrix
license: GPL3+
document version: 1.1
modified: 01/17/2018
author: David Schenck