From 0725b1bc5874de06a01174d973a60b8d73396f64 Mon Sep 17 00:00:00 2001
From: Gaspard Jankowiak <gaspard.jankowiak@uni-graz.at>
Date: Mon, 10 Feb 2025 12:26:36 +0100
Subject: [PATCH] add docstring and update README

---
 README.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/README.md b/README.md
index 9ca484a..2a6c3fc 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,20 @@
 # TaylorTest
 
 Simple package to check derivatives
+
+# Usage
+
+```
+  check(f, Jf, x[, constant_components]; f_kwargs...)
+```
+
+Returns true if `Jf` approximates the derivative/gradient/Jacobian of `f` at point `x` (along a random direction).
+`f_kwargs` are keywords arguments to be passed to `f` and `Jf`.
+`constant_components` is an optional `Vector{Int}` corresponding to components of the direction which should be set to zero,
+effectively ignoring the dependency of `f` on these components.
+
+## Examples
+```julia-repl
+julia> f = x -> cos(x); Jf = x -> -sin(x); check(f, Jf, rand())
+true
+```