-module(gleam_synapses@model@net_elems@activation@activation).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([f/1, deriv/1, inverse/1, generator/0]).
-export_type([activation/0]).

-type activation() :: sigmoid | identity | tanh | leaky_re_lu.

-file("/home/dimos/Projects/Gleam/gleam_synapses/src/gleam_synapses/model/net_elems/activation/activation.gleam", 12).
-spec sigmoid_f(float()) -> float().
sigmoid_f(X) ->
    case (1.0 + math:exp(+0.0 - X)) of
        +0.0 -> +0.0;
        -0.0 -> -0.0;
        Gleam@denominator -> 1.0 / Gleam@denominator
    end.

-file("/home/dimos/Projects/Gleam/gleam_synapses/src/gleam_synapses/model/net_elems/activation/activation.gleam", 16).
-spec f(activation()) -> fun((float()) -> float()).
f(Activation) ->
    case Activation of
        sigmoid ->
            fun sigmoid_f/1;

        identity ->
            fun gleam@function:identity/1;

        tanh ->
            fun math:tanh/1;

        leaky_re_lu ->
            fun(X) -> case X < +0.0 of
                    true ->
                        0.01 * X;

                    false ->
                        X
                end end
    end.

-file("/home/dimos/Projects/Gleam/gleam_synapses/src/gleam_synapses/model/net_elems/activation/activation.gleam", 30).
-spec deriv(activation()) -> fun((float()) -> float()).
deriv(Activation) ->
    case Activation of
        sigmoid ->
            fun(D) -> sigmoid_f(D) * (1.0 - sigmoid_f(D)) end;

        identity ->
            fun(_) -> 1.0 end;

        tanh ->
            fun(D@1) -> 1.0 - (math:tanh(D@1) * math:tanh(D@1)) end;

        leaky_re_lu ->
            fun(D@2) -> case D@2 < +0.0 of
                    true ->
                        0.01;

                    false ->
                        1.0
                end end
    end.

-file("/home/dimos/Projects/Gleam/gleam_synapses/src/gleam_synapses/model/net_elems/activation/activation.gleam", 44).
-spec inverse(activation()) -> fun((float()) -> float()).
inverse(Activation) ->
    case Activation of
        sigmoid ->
            fun(Y) ->
                T = case (1.0 - Y) of
                    +0.0 -> +0.0;
                    -0.0 -> -0.0;
                    Gleam@denominator -> Y / Gleam@denominator
                end,
                math:log(T)
            end;

        identity ->
            fun gleam@function:identity/1;

        tanh ->
            fun(Y@1) -> 0.5 * math:log(case (1.0 - Y@1) of
                        +0.0 -> +0.0;
                        -0.0 -> -0.0;
                        Gleam@denominator@1 -> (1.0 + Y@1) / Gleam@denominator@1
                    end) end;

        leaky_re_lu ->
            fun(Y@2) -> case Y@2 < +0.0 of
                    true ->
                        Y@2 / 0.01;

                    false ->
                        Y@2
                end end
    end.

-file("/home/dimos/Projects/Gleam/gleam_synapses/src/gleam_synapses/model/net_elems/activation/activation.gleam", 61).
-spec generator() -> minigen:generator(activation()).
generator() ->
    minigen:always(sigmoid).