From 09656bfd7ba9cb6c85b44a1f6a306dd918c8f78c Mon Sep 17 00:00:00 2001
From: Simon Vervisch <44346751+SimonVervisch@users.noreply.github.com>
Date: Sat, 11 Jan 2025 15:38:20 +0100
Subject: [PATCH 1/2] basic initial version of brownian motion

---
 Cargo.toml      |  2 ++
 src/brownian.rs | 41 +++++++++++++++++++++++++++++++++++++++++
 src/lib.rs      |  1 +
 3 files changed, 44 insertions(+)
 create mode 100644 src/brownian.rs

diff --git a/Cargo.toml b/Cargo.toml
index dfca7ae..d4a5a96 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,8 @@ edition = "2021"
 
 [dependencies]
 num-traits = "0.2.19"
+rand_distr = "0.4"
+rand="0.8"
 
 [lib]
 
diff --git a/src/brownian.rs b/src/brownian.rs
new file mode 100644
index 0000000..8049539
--- /dev/null
+++ b/src/brownian.rs
@@ -0,0 +1,41 @@
+use num_traits::Num;
+use rand_distr::{Normal, Distribution};
+use crate::{storage::DimensionalStorage, Dimensional};
+use std::ops::AddAssign;
+
+// TODO: make it work for all types (now works only for floating types)
+// TODO: have the option to save the path of the walk (although may be costly)
+
+
+fn brownian_motion<T, S, const N: usize>(dimensional: &mut Dimensional<T, S, N>, std_dev: f64, n_steps: usize) 
+where
+    T: Num + Copy + AddAssign ,
+    f64: Into<T>,
+    S: DimensionalStorage<T, N>,
+{
+    let normal = Normal::new(0.0, std_dev).unwrap();
+    let length_dimensional = dimensional.len();
+    let mut iter = dimensional.iter_mut();
+    for _ in 1..=length_dimensional {
+        if let Some(elem) = iter.next() {
+            for _ in 0..n_steps{
+                *elem += normal.sample(&mut rand::thread_rng()).into();
+            }
+        }
+    }
+
+}
+
+mod tests {
+    use crate::{Dimensional, LinearArrayStorage};
+    
+
+    #[test]
+    fn test_len() {
+        let mut zeros: Dimensional<f64, LinearArrayStorage<f64, 2>, 2> = Dimensional::zeros([2, 3]);
+        brownian_motion(&mut zeros,0.1, 1000);  
+        println!("{}", format!("{}", zeros));
+    
+    }
+
+}
diff --git a/src/lib.rs b/src/lib.rs
index b148a2c..b4fd809 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -50,6 +50,7 @@ mod display;
 mod iterators;
 mod operators;
 mod storage;
+mod brownian;
 
 // Public API
 pub use crate::core::Dimensional;

From 1a98881ae62e7daaea7524c13973b01b68fc4f2d Mon Sep 17 00:00:00 2001
From: Simon Vervisch <44346751+SimonVervisch@users.noreply.github.com>
Date: Sat, 11 Jan 2025 15:47:05 +0100
Subject: [PATCH 2/2] include brownian motion

---
 src/brownian.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/brownian.rs b/src/brownian.rs
index 8049539..dd7230f 100644
--- a/src/brownian.rs
+++ b/src/brownian.rs
@@ -27,7 +27,7 @@ where
 }
 
 mod tests {
-    use crate::{Dimensional, LinearArrayStorage};
+    use crate::{brownian::brownian_motion, Dimensional, LinearArrayStorage};
     
 
     #[test]