Trying to implement projective transform in elixir.

I ported an algorithm over from another project:

```
defmodule ProjectiveTransform do
def make_transform(
[[x1, y1], [x2, y2], [x3, y3], [x4, y4]],
[[xx1, yy1], [xx2, yy2], [xx3, yy3], [xx4, yy4]]
) do
make_transform(
[x1, y1, x2, y2, x3, y3, x4, y4],
[xx1, yy1, xx2, yy2, xx3, yy3, xx4, yy4])
end
def make_transform(
[x1, y1, x2, y2, x3, y3, x4, y4],
[xx1, yy1, xx2, yy2, xx3, yy3, xx4, yy4]
) do
a = Nx.tensor([
[x1, y1, 1, 0, 0, 0, 0, 0, -xx1, 0, 0, 0],
[x2, y2, 1, 0, 0, 0, 0, 0, 0 ,-xx2, 0, 0],
[x3, y3, 1, 0, 0, 0, 0, 0, 0, 0 ,-xx3, 0],
[x4, y4, 1, 0, 0, 0, 0, 0, 0, 0, 0 ,-xx4],
[0, 0, 0, x1, y1, 1, 0, 0, -yy1, 0, 0, 0],
[0, 0, 0, x2, y2, 1, 0, 0, 0 ,-yy2, 0, 0],
[0, 0, 0, x3, y3, 1, 0, 0, 0, 0 ,-yy3, 0],
[0, 0, 0, x4, y4, 1, 0, 0, 0, 0, 0 ,-yy4],
[0, 0, 0, 0, 0, 0, x1, y1, -1, 0, 0, 0],
[0, 0, 0, 0, 0, 0, x2, y2, 0 ,-1, 0, 0],
[0, 0, 0, 0, 0, 0, x3, y3, 0, 0 ,-1, 0],
[0, 0, 0, 0, 0, 0, x4, y4, 0, 0, 0 ,-1],
])
v = Nx.tensor([0, 0, 0, 0, 0, 0, 0, 0, -1, -1, -1, -1])
x = Nx.LinAlg.solve(a, v)
Nx.reshape(Nx.concatenate([x[0..7], Nx.tensor([1])]), {3,3})
end
end
```

Then wrote a simple test

```
defmodule ProjectiveTransformTest do
use ExUnit.Case, async: true
use ExUnitProperties
alias StreamData
import TestHelpers
test "single hardcoded transformation case" do
assert ProjectiveTransform.make_transform(
[[0,0], [0,10], [10,10], [10,0]],
[[0,0], [0,10], [10,10], [10,0]]
) == Nx.eye(3)
end
end
```

And when I run `mix test`

I get the following error:

```
2) test single hardcoded transformation case (ProjectiveTransformTest)
test/object_tracking_test.exs:57
Assertion with == failed
code: assert ProjectiveTransform.make_transform([[0, 0], [0, 10], ~c"\n\n", [10, 0]], [
[0, 0],
[0, 10],
~c"\n\n",
[10, 0]
]) == Nx.eye(3)
left: #Nx.Tensor<\n f32[3][3]\n [\n [1.0000011920928955, -2.006071753157812e-7, 1.415989459019329e-6],\n [9.025153069330827e-9, 1.000001072883606, -2.960541394259053e-7],\n [8.9426798410841e-8, 5.948747983097746e-8, 1.0]\n ]\n>
right: #Nx.Tensor<\n s64[3][3]\n [\n [1, 0, 0],\n [0, 1, 0],\n [0, 0, 1]\n ]\n>
```

For comparison, the same exact thing in Julia:

```
julia> make_perspective(((0,0), (0,10), (10,10), (10,0)), ((0,0), (0,10), (10,10), (10,0)))
3Ă—3 SMatrix{3, 3, Float64, 9} with indices SOneTo(3)Ă—SOneTo(3):
1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0
```

It looks like itâ€™s â€ścloseâ€ť to zero but why e-7?