Counting characters occurrences in String

[Jean Duarte]

Hi folks.

Is there any simpler way to count characters occurences other than this?

Enum.group_by(~w{A G C T T T T C A}, &Base.encode16/1) |> Dict.values |> Enum.map(&Enum.count/1)


I saw similar code in Python which looks like this:

s.count("A"), s.count("G"), s.count("C"), s.count("T")

Cheers

[r...@dimpixel.com]

I did this in a test script a few weeks ago using Enum.reduce. This is what I came up with using Map, you could convert to Dict:

Enum.reduce ~w{A G C T T T T C A}, %{}, fn(letter, acc) ->

  count = Map.get(acc, letter) || 0

  Map.put(acc, letter, count+1)

end

- Rob

[José Valim]

Using Map API is better if you know it is a map (which you do in your case). The next step is to change it to use Map.update/4 instead of doing 2 operations. :)

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[r...@dimpixel.com]

That's great, I didn't know that Map.update/4 was a thing! :)

Enum.reduce ~w{A G C T T T T C A}, %{}, fn(letter, acc) ->

  Map.update(acc, letter, 1, &(&1 + 1))

end

On Monday, March 2, 2015 at 11:57:32 AM UTC-7, José Valim wrote:

Using Map API is better if you know it is a map (which you do in your case). The next step is to change it to use Map.update/4 instead of doing 2 operations. :)

On Monday, March 2, 2015, <r...@dimpixel.com> wrote:

I did this in a test script a few weeks ago using Enum.reduce. This is what I came up with using Map, you could convert to Dict:

Enum.reduce ~w{A G C T T T T C A}, %{}, fn(letter, acc) ->

  count = Map.get(acc, letter) || 0

  Map.put(acc, letter, count+1)

end

- Rob

On Monday, March 2, 2015 at 11:46:26 AM UTC-7, Jean Duarte wrote:

Hi folks.

Is there any simpler way to count characters occurences other than this?

Enum.group_by(~w{A G C T T T T C A}, &Base.encode16/1) |> Dict.values |> Enum.map(&Enum.count/1)


I saw similar code in Python which looks like this:

s.count("A"), s.count("G"), s.count("C"), s.count("T")

Cheers

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[Jean Duarte]

Thanks guys.

Far simpler and clearer than expected ;)