# Spiral Matrix

Given the size, return a square matrix of numbers in spiral order.

The matrix should be filled with natural numbers, starting from 1
in the top-left corner, increasing in an inward, clockwise spiral order,
like these examples:

###### Spiral matrix of size 3

```plain
1 2 3
8 9 4
7 6 5
```

###### Spiral matrix of size 4

```plain
 1  2  3 4
12 13 14 5
11 16 15 6
10  9  8 7
```

## Running tests

In order to run the tests, issue the following command from the exercise
directory:

For running the tests provided, `rebar3` is used as it is the official build and
dependency management tool for erlang now. Please refer to [the tracks installation
instructions](http://exercism.io/languages/erlang/installation) on how to do that.

In order to run the tests, you can issue the following command from the exercise
directory.

```bash
$ rebar3 eunit
```

### Test versioning

Each problem defines a macro `TEST_VERSION` in the test file and
verifies that the solution defines and exports a function `test_version`
returning that same value.

To make tests pass, add the following to your solution:

```erlang
-export([test_version/0]).

test_version() ->
  1.
```

The benefit of this is that reviewers can see against which test version
an iteration was written if, for example, a previously posted solution
does not solve the current problem or passes current tests.

## Questions?

For detailed information about the Erlang track, please refer to the
[help page](http://exercism.io/languages/erlang) on the Exercism site.
This covers the basic information on setting up the development
environment expected by the exercises.

## Source

Reddit r/dailyprogrammer challenge #320 [Easy] Spiral Ascension. [https://www.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/](https://www.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.