Simple Grid

I noticed I kept reimplementing the same 2d-grid structure in many of my personal projects, so I decided to make it into a library. This data structure does not attempt to be the fastest or best implementation of a 2d-grid, but it's simple to use and has zero dependencies.

Example usage

Creating a grid and accessing its cells:

```rust use simple_grid::Grid;

let grid = Grid::new(10, 10, (1..=100).collect::>()); assert_eq!(grid.get((5, 2)).unwrap(), &26);

println!("{}", grid.toprettystring()); // prints: // 1 2 3 4 5 6 7 8 9 10 // 11 12 13 14 15 16 17 18 19 20 // 21 22 23 24 25 26 27 28 29 30 // 31 32 33 34 35 36 37 38 39 40 // 41 42 43 44 45 46 47 48 49 50 // 51 52 53 54 55 56 57 58 59 60 // 61 62 63 64 65 66 67 68 69 70 // 71 72 73 74 75 76 77 78 79 80 // 81 82 83 84 85 86 87 88 89 90 // 91 92 93 94 95 96 97 98 99 100 ```

Iterating over cells:

```rust let grid = Grid::new(10, 10, (1..=100).collect::>());

let elementsinrow3: Vec = grid.rowiter(3).copied().collect(); asserteq!( elementsinrow3, vec![31, 32, 33, 34, 35, 36, 37, 38, 39, 40] );

let elementsincolumn7: Vec = grid.columniter(7).copied().collect(); asserteq!( elementsincolumn7, vec![8, 18, 28, 38, 48, 58, 68, 78, 88, 98] ); ```

Modifying contents

```rust let mut grid = Grid::new(10, 10, (1..=100).collect::>());

// get a mutable reference to a cell *grid.getmut((8, 2)).unwrap() = 1000; asserteq!(grid.get((8, 2)).unwrap(), &1000);

// can also access directly via the index operator grid[(5,5)] = 1001; assert_eq!(grid.get((5, 5)).unwrap(), &1001); ```

Serializing/deserializing

This is only available if the serde feature is enabled.

Linear algebra

The linalg feature includes some methods that are useful for linear algebra:

Arithmetic operations:

rust let grid1 = Grid::new(2, 2, vec![1, 2, 3, 4]); let grid2 = Grid::new(2, 2, vec![1, 0, 1, 0]); let sum = grid1 + grid2; assert_eq!(sum, Grid::new(2, 2, vec![2, 2, 4, 4]));

Inverse, transpose etc.:

rust let grid = Grid::new(3, 3, vec![3., 0., 2., 2., 0., -2., 0., 1., 1.]); let inverse = grid.inverse().unwrap(); for (actual, expected) in inverse .cell_iter() .zip(Grid::new(3, 3, vec![0.2, 0.2, 0., -0.2, 0.3, 1.0, 0.2, -0.3, 0.]).cell_iter()) { let diff = actual - expected; assert!(diff < 0.000001); }

Gaussian elimination

To solve the following system:

2x + y - z = 8

-3x - y + 2z = -11

-2x + y + 2z = -3 rust // the equation system represented as a Grid where the rightmost column is the right side of the equal signs let mut grid = Grid::new( 4, 3, vec![2., 1., -1., 8., -3., -1., 2., -11., -2., 1., 2., -3.], ); let solution = grid.gaussian_elimination(); assert_eq!(solution.unwrap_single_solution(), vec![2., 3., -1.])) Giving the solution x = 2, y = 3, z = -1