(de)-serialize a matrix (#589)

* (de)-serialize a matrix

* enable serde-serialize for nalgebra

* fix typo

* add references

Cargo.toml

@@ -30,7 +30,7 @@ log = "0.4"
 log4rs = "0.8"
 memmap = "0.7"
 mime = "0.3"
-nalgebra = "0.16.12"
+nalgebra = { version = "0.16.12", features = ["serde-serialize"] }
 ndarray = { version = "0.13", features = ["approx"] }
 num = "0.2"
 num_cpus = "1.8"

src/science/mathematics/linear_algebra.md

@@ -6,5 +6,6 @@
 {{#include linear_algebra/vector-comparison.md}}
 {{#include linear_algebra/vector-norm.md}}
 {{#include linear_algebra/invert-matrix.md}}
+{{#include linear_algebra/deserialize-matrix.md}}
 
 {{#include ../../links.md}}

src/science/mathematics/linear_algebra/deserialize-matrix.md

@@ -0,0 +1,33 @@
+## (De)-Serialize a Matrix
+[![ndarray-badge]][ndarray] [![cat-science-badge]][cat-science]
+
+Serialize and deserialize a matrix to and from JSON. Serialization is taken care of
+by [`serde_json::to_string`] and [`serde_json::from_str`] performs deserialization.
+
+Note that serialization followed by deserialization gives back the original matrix.
+
+```rust
+extern crate nalgebra;
+extern crate serde_json;
+
+use nalgebra::DMatrix;
+
+fn main() -> Result<(), std::io::Error> {
+    let row_slice: Vec<i32> = (1..5001).collect();
+    let matrix = DMatrix::from_row_slice(50, 100, &row_slice);
+
+    // serialize matrix
+    let serialized_matrix = serde_json::to_string(&matrix)?;
+
+    // deserialize matrix
+    let deserialized_matrix: DMatrix<i32> = serde_json::from_str(&serialized_matrix)?;
+
+    // verify that `deserialized_matrix` is equal to `matrix`
+    assert!(deserialized_matrix == matrix);
+
+    Ok(())
+}
+```
+
+[`serde_json::to_string`]: https://docs.rs/serde_json/*/serde_json/fn.to_string.html
+[`serde_json::from_str`]: https://docs.rs/serde_json/*/serde_json/fn.from_str.html