Basic Linear Algebra and D's Array Operation

[Andrew Edwards]

Sooo... I'm trying to learn this stuff so that I can fully grasp 
the content of Jens Mueller's 2019 DConf talk and its 
applications in financial sector (forex and options/futures 
trading). Unfortunately, I'm doing so using python but I'd like 
to accomplish the same in D. Here goes:

Array (Vector) Algebra

	auto V = [1, 2, 3];
	auto v = V[] * 4; // v == [4, 8, 12]

Output:
	Error: array operation V[] * 4 without destination memory not 
allowed

Huh? What? That makes no sense, but okay... whatever.

	int[3] v = V[] * 4; // v == [4, 8, 12]
	v[] = v[] + v[]; // v == [8, 16, 24]
	v[] = v[] / 2; // v == [4, 8, 12]
	v[] = v[] - v[]; // v = [0, 0, 0]

so far so good. On to the fun stuff.

Multidimensional Array (Matrix) Algebra

	auto M = [[1, 2, 3], [1, 2, 3], [1,2,3]];
	int[3][3] m = M[] * 4;
	
Output:
	Error: incompatible types for (M[]) * (4): int[][] and int

Okay, I'm lost on that one. But let's press on.

	int[3][3] m = M[] * [[4]];

Output:
	Error: cannot implicitly convert expression M[] * [[4]] of type 
int[][] to int[]

	int[3][3] m = M[] * [[4,4,4], [4,4,4], [4,4,4]];

Output:
	Error: cannot implicitly convert expression M[] * [[4, 4, 4], 
[4, 4, 4], [4, 4, 4]] of type int[][] to int[]

I'm so confused. Maybe it's the way I'm accessing M?

	int[3][3] m = M[][] * 4;

Output:
	Error: incompatible types for (M[]) * (4): int[][] and int

And... it begins again!!!

So the question is, how do I pull this off in D using just 
builtin arrays and phobos?

Any assistance is appreciated.

Thanks,
Andrew

P.S. Why do we still have two sets of documentations ([1],[2]) 
for the language? Which is the official one and when can we get 
rid of the other?

[1] https://dlang.org/library/std/array.html
[2] https://dlang.org/phobos/std_array.html