diff options
| -rw-r--r-- | polymatrix/__init__.py | 9 | ||||
| -rw-r--r-- | polymatrix/expression/__init__.py | 5 | ||||
| -rw-r--r-- | polymatrix/expression/mixins/lowertriangularexprmixin.py | 7 |
3 files changed, 16 insertions, 5 deletions
diff --git a/polymatrix/__init__.py b/polymatrix/__init__.py index 62fc4a6..33ad143 100644 --- a/polymatrix/__init__.py +++ b/polymatrix/__init__.py @@ -15,6 +15,8 @@ from polymatrix.expression import ( v_stack as internal_v_stack, h_stack as internal_h_stack, product as internal_product, + block_diag as internal_block_diag, + lower_triangular as internal_lower_triangular, ) from polymatrix.expression.to import ( @@ -34,12 +36,15 @@ make_state = init_expression_state v_stack = internal_v_stack h_stack = internal_h_stack product = internal_product +block_diag = internal_block_diag +lower_triangular = internal_lower_triangular to_constant_repr = internal_to_constant -to_constant = internal_to_constant to_sympy_repr = internal_to_sympy -to_sympy = internal_to_sympy to_matrix_repr = from_polymatrix + +to_constant = internal_to_constant +to_sympy = internal_to_sympy to_dense = from_polymatrix to_affine = to_affine_expression diff --git a/polymatrix/expression/__init__.py b/polymatrix/expression/__init__.py index f8b5b74..2864fc5 100644 --- a/polymatrix/expression/__init__.py +++ b/polymatrix/expression/__init__.py @@ -56,3 +56,8 @@ def product( stack=get_stack_lines(), ) ) + + +def lower_triangular(vector: Expression): + return init_expression( + underlying=polymatrix.expression.impl.LowerTriangularExprImpl(underlying=vector)) diff --git a/polymatrix/expression/mixins/lowertriangularexprmixin.py b/polymatrix/expression/mixins/lowertriangularexprmixin.py index 74368a4..5bdfb3e 100644 --- a/polymatrix/expression/mixins/lowertriangularexprmixin.py +++ b/polymatrix/expression/mixins/lowertriangularexprmixin.py @@ -44,14 +44,15 @@ class LowerTriangularExprMixin(ExpressionBaseMixin): n_float = .5 * (-1 + sqrt(1 + 8 * N)) if not isclose(int(n_float), n_float): raise ValueError("To construct a n x n lower triangular matrix, the vector " - "must be n * (n + 1) / 2 column dimensional.") + "must be an n * (n + 1) / 2 dimensional column.") n = int(n_float) p = PolyMatrixDict.empty() for row in range(n): - for col in range(row): - p[row, col] = u.at(row + col, 1) + i = row * (row + 1) // 2 + for col in range(row + 1): + p[row, col] = u.at(i + col, 0) return state, init_poly_matrix(p, shape=(n, n)) |