Module: JBLAS::MatrixAccessMixin

Mixin for all kinds of element access.

This mixin is collected into MatrixMixin.

You have the following options of accessing elements:

Linear access: accessing all elements linearly, going down rows first (x[i], x.get(i), x.put(i))
Two-dimensional access: Accessing element in row i, column j (x[i,j], x.get(i,j), x.put(i,j)
Accessing rows and columns: get_row(i), get_column(i), put_row(i), put_column(i), and also get_rows(i), get_columns(i).
Accessing row and column ranges: get_row_range, get_column_range, get_range

As indices, you can use one of the following:

Numbers: x[10], x[3,4], x.getRow(3), etc.
Indices as int[] arrays: Unfortunately, these are bit hard to construct in JRuby ([1,2,3].to_java :int), therefore the emthod to_indices is added to Numeric, Enumerable, Array, and the matrices. Then: `i = [1,2,3]; x`.
Matrices: In that case, x.find_indices is called to find the non-zero elements and use those as indices.
Ranges: See JBLAS::Ranges

For some access functions (in particular getting rows and columns), you can also specify where to copy the result to get better performance through suppressing object creations.

Methods

[] []= get_column get_column_range get_columns get_range get_row get_row_range get_rows to_indices

Public Instance methods

[](i, j=nil)

Get the entry at i, j. If j is omitted, linear addressing is used (that is, i just enumerates all entries going down rows first.)

As indices you can use numbers, int[] arrays, matrices (non-zero elements are taken as indices then), and ranges.

[Source]

# File lib/jblas/mixin_access.rb, line 90
    def [](i, j=nil)
      if j
        get(i.to_indices, j.to_indices)
      else
        get(i.to_indices)
      end
    end

[]=(i, j, v=nil)

Set the entry at i, j to v. If j is omitted, linear addressing is used (that is, i just enumerates all entries going down rows first.)

As indices you can use numbers, int[] arrays, matrices (non-zero elements are taken as indices then), and ranges.

[Source]

# File lib/jblas/mixin_access.rb, line 104
    def []=(i, j, v=nil)
      if v
        put(i.to_indices, j.to_indices, v)
      else
        put(i.to_indices, j)
      end
    end

get_column(i)

Get a column of a matrix. Unlike column(i) method, this method returns a copy of the given column.

[Source]

# File lib/jblas/mixin_access.rb, line 125
    def get_column(i); JAVA_METHOD; end

get_column_range(i, j1, j2)

Get a copy of columns j1 .. j2 - 1 from row i.

[Source]

# File lib/jblas/mixin_access.rb, line 137
    def get_column_range(i, j1, j2); JAVA_METHOD; end

get_columns(i)

Get a number of rows.

As indices you can use numbers, int[] arrays, matrices (non-zero elements are taken as indices then), and ranges.

[Source]

# File lib/jblas/mixin_access.rb, line 131
    def get_columns(i); JAVA_METHOD; end

get_range(i1, i2, j1, j2)

Get a copy of the submatrix with rows i1 .. i2 - 1 and columns j1 .. j2 - 1.

[Source]

# File lib/jblas/mixin_access.rb, line 141
    def get_range(i1, i2, j1, j2); JAVA_METHOD; end

get_row(i, result=nil)

Get row of a matrix. Unlike the row(i) method, this method returns a copy of the given row. If result is given, the row is copied in that matrix.

[Source]

# File lib/jblas/mixin_access.rb, line 115
    def get_row(i, result=nil); JAVA_METHOD; end

get_row_range(i1, i2, j)

Get a copy of rows i1 .. i2 - 1 from column j.

[Source]

# File lib/jblas/mixin_access.rb, line 134
    def get_row_range(i1, i2, j); JAVA_METHOD; end

get_rows(i)

Get a number of rows.

As indices you can use numbers, int[] arrays, matrices (non-zero elements are taken as indices then), and ranges.

[Source]

# File lib/jblas/mixin_access.rb, line 121
    def get_rows(i); JAVA_METHOD; end

to_indices()

Return an array usable as an index.

[Source]

# File lib/jblas/mixin_access.rb, line 144
    def to_indices
      self
    end