38 lines
723 B
Erlang
38 lines
723 B
Erlang
%% Handle missing log2 prior to OTP18
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-module(leveled_math).
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%% API
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-export([
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log2/1
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]).
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-include_lib("eunit/include/eunit.hrl").
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%%%===================================================================
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%%% Use log2
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%%%===================================================================
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-ifndef(no_log2).
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log2(X) ->
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math:log2(X).
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-else.
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%%%===================================================================
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%%% Old (r18) random style functions
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%%%===================================================================
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log2(X) ->
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math:log(X) / 0.6931471805599453.
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-endif.
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-ifdef(TEST).
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log2_test() ->
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?assertMatch(8, round(log2(256))),
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?assertMatch(16, round(log2(65536))).
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-endif.
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