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LaTeX Guidelines

LaTeX Guidelines

This notation guide is inspired by Deep Learning by Ian Goodfellow, Yoshua Bengio and Aaron Courville (opens in a new tab) whilst trying to stay short and compatible with KaTeX (opens in a new tab) (Docusaurus support) and MathJax (opens in a new tab) (Jupyter Notebook support). This page is also meant as a cheat sheet for me on latex structures such as matrices etc.

Numbers and Arrays

If we wanted tensors to also be bold we would have to write \mathsf{\boldsymbol{A}} which is sadly not nice and short.

DescriptionCodeExample
Scalar (integer or real)a=2aa
Vector, lowercase italic bold\boldsymbol{a}a\boldsymbol{a}
Matrix, uppercase italic bold\boldsymbol{A}A\boldsymbol{A}
Tensor, uppercase sans-serif\mathsf{A}A\mathsf{A}
Identity matrix with nn rows and nn columns\boldsymbol{I}_nIn\boldsymbol{I}_n
Identity matrix with implied dimensionality\boldsymbol{I}I\boldsymbol{I}
Square diagonal matrix with elements along main diagonal given by a\boldsymbol{a}\text{diag}(\boldsymbol{a})diag(a)\text{diag}(\boldsymbol{a})

Indexing

DescriptionCodeExample
Element ii of vector a\boldsymbol{a}, with indexing starting at 1a_iaia_i
All elements of vector a\boldsymbol{a} except for element iia_{-i}aia_{-i}
Element i,ji,j of matrix A\boldsymbol{A}, with ii corresponding to the row index and jj the column indexA_{i,j} or a_{ij}Ai,jA_{i,j} or aija_{ij}
Row ii of matrix A\boldsymbol{A}\boldsymbol{A}_{i,:}Ai,:\boldsymbol{A}_{i , :}
Column jj of matrix A\boldsymbol{A}\boldsymbol{A}_{:,j}A:,j\boldsymbol{A}_{: , j}

Linear Algebra Operations

DescriptionCodeExample
Tranpose of matrix A\boldsymbol{A}\boldsymbol{A}^TAT\boldsymbol{A}^T
Moore-Penrose pseudoinverse of matrix A\boldsymbol{A}\boldsymbol{A}^\daggerA\boldsymbol{A}^\dagger
Hadamard (element-wise) product of A\boldsymbol{A} and B\boldsymbol{B}\boldsymbol{A} \odot boldsymbol{B}AB\boldsymbol{A} \odot \boldsymbol{B}
Determinant of matrix A\boldsymbol{A}\text{det}(\boldsymbol{A})det(A)\text{det}(\boldsymbol{A})
Trace of matrix A\boldsymbol{A}\text{tr}(\boldsymbol{A})tr(A)\text{tr}(\boldsymbol{A})

Sets and Graphs

DescriptionCodeExample
SetAAA
Set of natural numbers, including 00\Bbb{N}=\{0,1,2,3,...\}N={0,1,2,3,...}\Bbb{N}=\{0,1,2,3,...\}
Set of integer numbers\Bbb{Z}Z\Bbb{Z}
Set of rational numbers\Bbb{Q}Q\Bbb{Q}
Set of irrational numbers\Bbb{I}I\Bbb{I}
Set of real numbers\Bbb{R}R\Bbb{R}
Set of complex numbers\Bbb{C}C\Bbb{C}