2-D array initialization

[tastyminerals]

On Sunday, 2 August 2020 at 19:19:51 UTC, Andy Balba wrote:
> On Sunday, 2 August 2020 at 06:37:06 UTC, tastyminerals wrote:
>
>> You haven't said anything about efficiency because if you care 
>> and your arrays are rather big, you better go with 
>> https://github.com/libmir/mir-algorithm as mentioned above. It 
>> might be a little finicky at the start but this post: 
>> https://tastyminerals.github.io/tasty-blog/dlang/2020/03/22/multidimensional_arrays_in_d.html should get you up to speed.
>>
>>
>> Keep in mind that std.array.staticArray is not efficient for  
>> large arrays.
>>
>> If you want to stick to standard D, I would not initialize a 
>> 2D array because it is just cumbersome but rather use a 1D 
>> array and transform it into 2D view on demand via ".chunks" 
>> method. Here is an example.
>>
>> import std.range;
>> import std.array;
>>
>> void main() {
>>     int[] arr = 20.iota.array;
>>     auto arr2dView = arr.chunks(5);
>> }
>>
>> Should give you
>>
>> ┌              ┐
>> │ 0  1  2  3  4│
>> │ 5  6  7  8  9│
>> │10 11 12 13 14│
>> │15 16 17 18 19│
>> └              ┘
>>
>> whenever you need to access its elements as arr.chunks(5)[1][1 
>> .. 3] --> [6, 7].
>
> @ tastyminerals  Thanks for your help on this. These comments, 
> combined with the others, are making my climb of the D learning 
> curve much quicker.
>
> I'm not a gitHub fan, but I like the mir functions; and it 
> looks like I have to download mir before using it.
> mir has quite a few .d files..Is there a quick way to download 
> it ?

mir is a D package (akin to Python pip package). You can easily 
include it into your program by adding at the top of your file 
the following code:

/+ dub.sdl:
     name "my_script"
     dependency "mir-algorithm" version="~>3.9.12"
+/

And then just run your script with "dub my_script.d", dub will 
fetch the necessary dependencies, compile and run the file. 
However, it will not generate compiled versions of your 
my_script.d for that, you better set a dub project. Here, see to 
do it: 
https://tastyminerals.github.io/tasty-blog/dlang/2020/03/01/how_to_use_external_libraries_in_d_project.html