Register SignALSH as the default hash function for inner_prod similarity.

Author: kernelmethod

src/hashes/lshfunction.jl

@@ -70,3 +70,4 @@ Associate similarity functions with LSHFunction subtypes
 @register_similarity!(ℓ1, L1Hash)
 @register_similarity!(ℓ2, L2Hash)
 @register_similarity!(jaccard, MinHash)
+@register_similarity!(inner_prod, SignALSH)

src/hashes/mips_hash.jl

@@ -230,6 +230,7 @@ LSHFunction and AsymmetricLSHFunction API compliance
 ========================#
 index_hash(hashfn::MIPSHash, x) = MIPSHash_P(hashfn, x)
 query_hash(hashfn::MIPSHash, x) = MIPSHash_Q(hashfn, x)
+similarity(::MIPSHash) = inner_prod
 
 n_hashes(hashfn::MIPSHash) = length(hashfn.shift)
 hashtype(::MIPSHash) = Vector{Int32}

test/test_lshfunction.jl renamed to test/hashes/test_lshfunction.jl

@@ -6,7 +6,7 @@ Tests for the LSHFunction() function for constructing hash functions.
 
 using Test, Random, LSH
 
-include("utils.jl")
+include(joinpath("..", "utils.jl"))
 
 #==================
 Tests
@@ -40,6 +40,20 @@ Tests
         @test isa(hashfn, MinHash)
     end
 
+    @testset "Create inner product similarity hash function" begin
+        hashfn = LSHFunction(inner_prod, 10; maxnorm=1)
+
+        @test similarity(hashfn) == inner_prod
+        @test n_hashes(hashfn) == 10
+        @test isa(hashfn, SignALSH)
+
+        # Test that same exceptions are thrown for invalid construction of
+        # SignALSH
+        @test_throws ErrorException LSHFunction(inner_prod, -1; maxnorm=10)
+        @test_throws ErrorException LSHFunction(inner_prod; m=0, maxnorm=10)
+        @test_throws ErrorException LSHFunction(inner_prod)
+    end
+
     @testset "Call LSHFunction() with invalid similarity function" begin
         import LinearAlgebra: dot, norm
         my_cossim(x,y) = dot(x,y) / (norm(x) * norm(y))

test/runtests.jl

@@ -24,8 +24,7 @@ include(joinpath("hashes", "test_minhash.jl"))
 include(joinpath("hashes", "test_lphash.jl"))
 include(joinpath("hashes", "test_mips_hash.jl"))
 include(joinpath("hashes", "test_sign_alsh.jl"))
-
-include("test_lshfunction.jl")
+include(joinpath("hashes", "test_lshfunction.jl"))
 
 include(joinpath("function_hashing", "test_monte_carlo.jl"))
 include(joinpath("function_hashing", "test_chebhash.jl"))