added invert-matrix to /science/mathematics/linear_algebra (#508)

* added invert-matrix to /science/mathematics/linear_algebra

* added nalgebra as dependency

* added nalgebra to dictionary

* fixed link to nalgebra

* Remove statistics file only includes the header

Cargo.toml

@@ -51,6 +51,7 @@ toml = "0.4"
 url = "1.6"
 walkdir = "2.0"
 ansi_term = "0.11.0"
+nalgebra = "0.16.12"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 syslog = "4.0"

ci/dictionary.txt

@@ -193,6 +193,7 @@ NaiveDate
 NaiveDateTime
 NaiveTime
 ndarray
+nalgebra
 nFun
 NotFound
 NulError

src/links.md

@@ -92,6 +92,8 @@ Keep lines sorted.
 [memmap]: https://docs.rs/memmap/
 [mime-badge]: https://badge-cache.kominick.com/crates/v/csv.svg?label=mime
 [mime]: https://docs.rs/mime/
+[nalgebra-badge]: https://badge-cache.kominick.com/crate/nalgebra.svg?label=nalgebra
+[nalgebra]: https://docs.rs/nalgebra
 [ndarray-badge]: https://badge-cache.kominick.com/crate/ndarray.svg?label=ndarray
 [ndarray]: https://docs.rs/ndarray
 [num-badge]: https://badge-cache.kominick.com/crates/v/num.svg?label=num

src/science/mathematics.md

@@ -7,6 +7,7 @@
 | [Adding matrices][add-matrices] | [![ndarray-badge]][ndarray] | [![cat-science-badge]][cat-science] |
 | [Multiplying matrices][multiply-matrices] | [![ndarray-badge]][ndarray] | [![cat-science-badge]][cat-science] |
 | [Multiply a scalar with a vector with a matrix][multiply-scalar-vector-matrix] | [![ndarray-badge]][ndarray] | [![cat-science-badge]][cat-science] |
+| [Invert marix][invert-matrix] | [![nalgebra-badge]][nalgebra] | [![cat-science-badge]][cat-science] |
 | [Calculating the side length of a triangle][side-length] | [![std-badge]][std] | [![cat-science-badge]][cat-science] |
 | [Verifying tan is equal to sin divided by cos][tan-sin-cos] | [![std-badge]][std] | [![cat-science-badge]][cat-science] |
 | [Distance between two points on the Earth][latitude-longitude] | [![std-badge]][std] | [![cat-science-badge]][cat-science] |
@@ -22,6 +23,7 @@
 [add-matrices]: science/mathematics/linear_algebra.html#adding-matrices
 [multiply-matrices]: science/mathematics/linear_algebra.html#multiplying-matrices
 [multiply-scalar-vector-matrix]: science/mathematics/linear_algebra.html#multiply-a-scalar-with-a-vector-with-a-matrix
+[invert-matrix]: science/mathematics/linear_algebra.html#invert-matrix
 [side-length]: science/mathematics/trigonometry.html#calculating-the-side-length-of-a-triangle
 [tan-sin-cos]: science/mathematics/trigonometry.html#verifying-tan-is-equal-to-sin-divided-by-cos
 [latitude-longitude]: science/mathematics/trigonometry.html#distance-between-two-points-on-the-earth

src/science/mathematics/linear_algebra.md

@@ -5,5 +5,6 @@
 {{#include linear_algebra/add-matrices.md}}
 {{#include linear_algebra/multiply-matrices.md}}
 {{#include linear_algebra/multiply-scalar-vector-matrix.md}}
+{{#include linear_algebra/invert-matrix.md}}
 
 {{#include ../../links.md}}

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

@@ -0,0 +1,25 @@
+## Invert matrix
+[![nalgebra-badge]][nalgebra] [![cat-science-badge]][cat-science]
+
+Creates a 3x3 matrix with [`nalgebra::Matrix3`] and inverts it, if possible.
+
+```rust
+extern crate nalgebra;
+
+use nalgebra::Matrix3;
+
+fn main() {
+    let m1 = Matrix3::new(2.0, 1.0, 1.0, 3.0, 2.0, 1.0, 2.0, 1.0, 2.0);
+    println!("m1 = {}", m1);
+    match m1.try_inverse() {
+        Some(inv) => {
+            println!("The inverse of m1 is: {}", inv);
+        }
+        None => {
+            println!("m1 is not invertible!");
+        }
+    }
+}
+```
+
+[`nalgebra::Matrix3`]: https://docs.rs/nalgebra/*/nalgebra/base/type.Matrix3.html