/ 
SPVM-R-0.100
River stage zero No dependents
/ SPVM::R::Util

Name

SPVM::R::Util - Utilities for N-Dimensional Array

Description

R::Util class in SPVM has utility methods for n-dimensional array.

Usage

use R::Util;

Class Methods

calc_data_length

static method calc_data_length : int ($dim : int[]);

Calcurates the data length from the dimensions $dim, and returns it.

The data length means the product of all elements in $dim.

Examples are

$dim       Return Value
[2, 3]     6
[1, 2, 3]  6

Exceptions:

The dimensions $dim must be normalized. Otherwise an exception is thrown.

normalize_dim

static method normalize_dim : int[] ($dim : int[]);

Normalizes the dimension $dim, and returns it.

See "is_normalized_dim" method about the normalization of dimensions.

Exceptions:

All element of the dimensions $dim except the last one must be greater than 0. Otherwise an exception is thrown.

is_normalized_dim

static method is_normalized_dim : int ($dim : int[]);

If the dimensions $dim is normalized, returns 1, otherwise returns 0.

Normalized dimensions mean that

  • $dim is defined.

  • And all elements of $dim are greater than 0 if elements exists.

check_length

static method check_length : void ($data : object, $dim : int[]);

Checks if the data $data that is an array and the dimensions $dim have length compatibility.

If they are satisfied, returns 1, otherwise returns 0.

length compatibility means the array length of $data is equal to the length calcurated by "calc_data_length" method.

Exceptions:

The data $data must be defined. Otherwise an exception is thrown.

The data $data must be an array. Otherwise an exception is thrown.

The dimensions $dim must be normalized. Otherwise an exception is thrown.

drop_dim

static method drop_dim : int[] ($dim : int[], $index : int = -1);

Case : $index < 0

$dim is copied and assigned to $dim.

If the length of the dimensions $dim is 0, returns $dim.

If not, removes all elements of $dim that are equal to 1. If $dim becomes [], [1] is assinged to $dim. And $dim is returned.

Examples are

$dim         Retrun value
[1, 2, 3]    [2, 3]
[1, 2, 1, 3] [2, 3]
[1, 1]       [1]
[1]          [1]
[]           []

Case : $index >= 0

$dim is copied and assigned to $dim.

If the element of $dim at index $index is 1, removes it, and returns $dim.

Exceptions:

The dimensions $dim must be normalized. Otherwise an exception is thrown.

The index $index must be less than the length of the dimension $dim.

The element of the dimension $dim at index $index must be 1. Otherwise an exception is thrown.

expand_dim

static method expand_dim : int[] ($dim : int[], $index : int = -1);

$dim is copied and assigned to $dim, inserts 1 to $dim at index $index, and returns $dim.

Exceptions:

The dimensions $dim must be normalized. Otherwise an exception is thrown.

The index $index must be less than or equal to the length of the dimension $dim.

equals_dim

static method equals_dim : int ($x_dim : int[], $y_dim : int[]);

If $x_dim is equal to $y_dim, returns 1, otherwise returns 0.

Exceptions:

The dimensions $x_dim must be normalized. Otherwise an exception is thrown.

The dimensions $y_dim must be normalized. Otherwise an exception is thrown.

equals_dropped_dim

static method equals_dropped_dim : int ($x_dim : int[], $y_dim : int[]);

If $x_dim on which "drop_dim" method is performed is equal to $y_dim on which "drop_dim" method is performed, returns 1, otherwise returns 0.

This method calls "equals_dim" method.

Exceptions:

Exceptions thrown by "equals_dim" method could be thrown.

Copyright & License

Copyright (c) 2024 Yuki Kimoto

MIT License