Diagonal Matrix¶
- class fastmat.Diag¶
Bases:
Matrix
\[x \mapsto {\mathrm{diag}}(d_1,\dots,d_n) \cdot x\]A diagonal matrix is uniquely defined by the entries of its diagonal.
>>> # import the package >>> import fastmat as fm >>> import numpy as np >>> >>> # build the parameters >>> n = 4 >>> d = np.array([1, 0, 3, 6]) >>> >>> # construct the matrix >>> D = fm.Diag(d)
This yields
\[d = (1, 0, 3, 6)^\mathrm{T}\]\[\begin{split}D = \begin{bmatrix} 1 & & & \\ & 0 & & \\ & & 3 & \\ & & & 6 \end{bmatrix}\end{split}\]- __init__()¶
Initialize a Diag matrix instance.
- Parameters
- vecD
numpy.ndarray
The generating vector of the diagonal entries of this matrix.
- **optionsoptional
Additional keyworded arguments. Supports all optional arguments supported by
fastmat.Matrix
.
- vecD
- vecD¶
Return the matrix-defining vector of diagonal entries.
(read-only)