# Numeric arrays¶

The Array type represents a numeric array with one or two dimensions.

## Array indexing¶

To get or set an element in an array, use the index [] operator. Elements along each dimension start at 1 and can be negative. (Negative indices start from the end of the dimension.) Two-dimensional arrays are accessed with a pair of indices noted (i, j), where i represents the i th row and j represents the j th column. For example, index (3, 2) represents the item in the third row in the second column, whereas (1, -1) represents element in the first row and in the last column.

var X = new Array(3, 4)
X[1,4] = 10
print(X[1,4])


## Global functions¶

read_matrix(path[, separator[, drop_header]])

Reads a two-dimensional numeric array from a CSV file, in which values are separated by separator (by default, a comma). If drop_header is true (default), the first line will be treated as a header and will be dropped.

write_matrix(M, path[, separator])

Writes a two-dimensional numeric array M to a CSV file, in which values are separated by separator (by default, a comma).

## Methods¶

class Array
Array(m[, n])

Constructs a vector with m elements or an m by n matrix. All elements are initialized to 0.

add(n)

Returns a new array where n was added to each element in the original array.

clone()

Returns a deep copy of the array.

div(n)

Returns a new array where each element in the original array was divided by n.

get_row(i)

Returns the i th row as a new one-dimensional array. The original array must be two-dimensional.

See also: get_column()

get_column(j)

Returns the j th column as a new one-dimensional array. The original array must be two-dimensional.

See also: get_row()

mul(n)

Returns a new array where each element in the original array was multiplied by n.

shuffle()

Randomly shuffles the elements of the array. This method modifies the array in place.

slice(d1_from, d1_to[, d2_from, d2_to])

Returns a new array which is a slice of the original array. If the original array has one dimension, the result is a one-dimensional array starting from index d1_from up to and including d1_to. If the array has two dimensions, the result is a matrix that includes rows starting from row d1_from up to and including row d1_to, and columns starting from d2_from up to and including row d2_to.

sub(n)

Returns a new array where n was subtracted from each element in the original array.

to_string()

Returns a string representation of the array.

transpose()

Returns the transpose of the matrix.

## Fields¶

dim_count

Returns the number of dimensions of the array.

column_count

Returns the number of columns in the array.

length

Returns the number of elements in the array.

row_count

Returns the number of rows in the array.