Python/R Math LaTeX Hover

Hover over any mathematical expression in Python or R and see it rendered as a beautiful LaTeX formula — right inside the editor tooltip.

Features

Instant LaTeX preview — hover over a formula and see the full expression rendered via MathJax, with no external dependencies or internet connection required at render time.
Sub-expression drill-down — the innermost parenthesized expression around your cursor is shown separately, letting you inspect nested formulas piece by piece.
Python & R support — works with math.*, numpy.*, np.*, scipy.*, and native R expressions. Also activates in R Markdown (.Rmd) and Quarto (.qmd) files, and inside Jupyter notebooks.
50+ built-in function mappings — trig, inverse trig, hyperbolic, exponential, logarithm, combinatorics, special functions, linear algebra, statistics, and more.
Automatic variable recognition — identifiers like sigma, alpha, mu, x_1, math.pi are automatically converted to the correct Greek letters and symbols.
Custom symbol mappings — define your own function-to-LaTeX templates in settings.json to match your project's naming conventions.
Theme-aware color — the SVG output uses currentColor and adapts to light and dark themes, with an explicit override option.
Non-intrusive — the LaTeX panel appears below the existing Pylance / R LSP definition, so you never lose your type information.

How It Works

The extension registers a hover provider for Python and R files. When you hold the cursor over a line containing a mathematical expression, it:

Parses the expression using a recursive-descent parser that understands Python and R syntax.
Converts the abstract syntax tree to a LaTeX string.
Renders the LaTeX to an SVG using MathJax (server-side, in the extension host process).
Embeds the SVG as a base64 data URL in the VS Code hover tooltip.

The MathJax instance is initialized once on activation and reused for all subsequent renders, so there is no startup cost per hover.

Requirements

VS Code 1.74 or later
Node.js 16 or later (required by mathjax-full, which is bundled)

Installation

From the Marketplace

Search for Python/R Math LaTeX Hover in the Extensions panel, or run:

ext install EnzoRSimette.math-latex-hover

From a `.vsix` file

# Clone and build
git clone https://github.com/EnzoRSimette/math-latex-hover
cd math-latex-hover
npm install
npm run compile

# Package
npm install -g @vscode/vsce
vsce package

# Install
code --install-extension math-latex-hover-0.1.0.vsix

Examples

Python code	Rendered formula
`math.cos(math.sqrt(abs((a+b)2) + abs((b-a)2)))`	cos(√(\|a+b\|² + \|b-a\|²))
`(math.log(S/K) + (r + sigma*2/2)T) / (sigma*math.sqrt(T))`	(ln(S/K) + (r + σ²/2)T) / (σ√T)
`(r_p - r_f) / math.sqrt(sigma**2)`	(rₚ − rᶠ) / √(σ²)
`math.comb(n, k) * p*k (1-p)**(n-k)`	C(n,k) · pᵏ · (1−p)ⁿ⁻ᵏ
`math.exp(-r * T)`	e^(−rT)

Configuration

All settings are under the Math LaTeX Hover section in VS Code settings.

Setting	Type	Default	Description
`mathLatexHover.enabled`	`boolean`	`true`	Enable or disable the extension.
`mathLatexHover.formulaColor`	`"auto"` \| `"white"` \| `"black"`	`"auto"`	Formula text color. Use `"white"` for dark themes or `"black"` for light themes.
`mathLatexHover.showCode`	`boolean`	`true`	Show the raw LaTeX source block below the rendered formula.
`mathLatexHover.extraDelay`	`number` (ms)	`0`	Additional delay on top of `editor.hover.delay` before the panel appears.
`mathLatexHover.customSymbols`	`object`	`{}`	Custom function and variable mappings (see below).

Custom Symbols

Map your own function and variable names to LaTeX templates in settings.json. Each {} in the template is replaced by the next function argument in order.

// .vscode/settings.json  (or User Settings)
{
  "mathLatexHover.customSymbols": {
    // mt.sum(x)    →  \sum{x}
    "mt.sum":  "\\sum{}",

    // mt.norm(v)   →  \|v\|
    "mt.norm": "\\left\\|{}\\right\\|",

    // mt.frac(a,b) →  \dfrac{a}{b}
    "mt.frac": "\\dfrac{}{}",

    // mt.EV(X)     →  \mathbb{E}[X]
    "mt.EV":   "\\mathbb{E}\\left[{}\\right]",

    // mt.var(X)    →  \mathbb{V}[X]
    "mt.var":  "\\mathbb{V}\\left[{}\\right]",

    // SIGMA used as a variable  →  \Sigma
    "SIGMA":   "\\Sigma"
  }
}

If a template has no {} placeholders and the function is called with arguments, they are appended automatically inside \left(\ldots\right). Changes take effect on the next hover — no reload required.

Built-in Function Reference

Trigonometric & Inverse

Code	LaTeX
`math.cos(x)` / `cos(x)`	`\cos(x)`
`math.sin(x)` / `sin(x)`	`\sin(x)`
`math.tan(x)` / `tan(x)`	`\tan(x)`
`math.acos(x)` / `acos(x)`	`\arccos(x)`
`math.asin(x)` / `asin(x)`	`\arcsin(x)`
`math.atan(x)` / `atan(x)`	`\arctan(x)`
`math.atan2(y, x)`	`\arctan(y/x)`
`math.cosh(x)` / `cosh(x)`	`\cosh(x)`
`math.sinh(x)` / `sinh(x)`	`\sinh(x)`
`math.tanh(x)` / `tanh(x)`	`\tanh(x)`

Roots, Powers & Logarithms

Code	LaTeX
`math.sqrt(x)` / `sqrt(x)`	`\sqrt{x}`
`math.cbrt(x)`	`\sqrt[3]{x}`
`math.exp(x)`	`e^{x}`
`math.log(x)`	`\ln(x)`
`math.log(x, b)`	`\log_b(x)`
`math.log2(x)`	`\log_2(x)`
`math.log10(x)`	`\log_{10}(x)`
`math.pow(x, n)` / `x**n`	`x^{n}`
`math.hypot(a, b)`	`\sqrt{a^2 + b^2}`

Rounding & Absolute Value

Code	LaTeX
`abs(x)` / `math.fabs(x)` / `np.abs(x)`	`\\|x\\|`
`math.floor(x)` / `floor(x)`	`\lfloor x \rfloor`
`math.ceil(x)` / `ceiling(x)`	`\lceil x \rceil`
`math.factorial(n)`	`n!`

Combinatorics

Code	LaTeX
`math.comb(n, k)` / `choose(n, k)`	`\binom{n}{k}`
`math.perm(n, k)`	`P(n, k)`
`math.gcd(a, b)`	`\gcd(a, b)`

Special Functions

Code	LaTeX
`math.erf(x)`	`\operatorname{erf}(x)`
`math.erfc(x)`	`\operatorname{erfc}(x)`
`math.gamma(x)`	`\Gamma(x)`
`math.lgamma(x)`	`\ln\Gamma(x)`

Linear Algebra (NumPy)

Code	LaTeX
`np.dot(a, b)`	`a \cdot b`
`np.cross(a, b)`	`a \times b`
`np.outer(a, b)`	`a \otimes b`
`np.linalg.norm(x)`	`\\|x\\|`
`np.linalg.det(A)`	`\det(A)`
`np.trace(A)`	`\operatorname{tr}(A)`
`np.linalg.inv(A)`	`A^{-1}`

Statistics

Code	LaTeX
`np.mean(x)`	`\bar{x}`
`np.std(x)`	`\sigma(x)`
`np.var(x)`	`\sigma^2(x)`
`np.sum(x)`	`\sum(x)`
`np.corrcoef(x, y)`	`\rho(x, y)`
`np.cov(x, y)`	`\operatorname{Cov}(x, y)`

Automatic Variable Recognition

Identifiers matching Greek letter names (e.g. alpha, sigma, mu, omega) are automatically converted to the corresponding LaTeX symbol. Underscore notation creates subscripts: x_1 → x_{1}, sigma_i → \sigma_{i}.

Built-in constants are also recognized: math.pi / np.pi → \pi, math.inf / np.inf → \infty, math.e → e.

Known Limitations

Only single-line expressions are supported (the line under the cursor).
Array indexing (x[0]), list comprehensions, and chained attribute access beyond module prefixes are not parsed.
Lambda expressions and walrus operators (:=) are not supported.

Contributing

Bug reports and pull requests are welcome on GitHub.

License

MIT

Python/R Math LaTeX Hover

Enzo R S

Python/R Math LaTeX Hover

Features

How It Works

Requirements

Installation

From the Marketplace

From a .vsix file

Examples

Configuration

Custom Symbols

Built-in Function Reference

Trigonometric & Inverse

Roots, Powers & Logarithms

Rounding & Absolute Value

Combinatorics

Special Functions

Linear Algebra (NumPy)

Statistics

Automatic Variable Recognition

Known Limitations

Contributing

License

From a `.vsix` file