BitVecCorrelation

Documentation

API Reference

BitVecCorrelation

Description

Calculate Pearson correlation coefficient between two bitvectors. Treats bits as 0/1 values and computes linear correlation.

Parameters

Name	Direction	Description
`bv1`	in	First bitvector
`bv2`	in	Second bitvector

Usage example (from documentation)

  double correlation = BitVecCorrelation(&bv1, &bv2);

Success

Returns the Pearson correlation coefficient in [-1.0, 1.0]. Neither operand is modified.

Failure

Returns 0.0 when either operand has zero variance (all bits equal); the caller cannot distinguish that from a true zero coefficient.

Usage example (Cross-references)

Usage examples (Cross-references)

In BitVec.c:1618:

    }
    
    double BitVecCorrelation(BitVec *bv1, BitVec *bv2) {
        ValidateBitVec(bv1);
        ValidateBitVec(bv2);

In Math.c:457:

        DefaultAllocator alloc = DefaultAllocatorInit();
    
        WriteFmt("Testing BitVecCorrelation basic functionality\n");
    
        BitVec bv1    = BitVecInit(ALLOCATOR_OF(&alloc));

In Math.c:473:

        BitVecPush(&bv2, false);
    
        double correlation = BitVecCorrelation(&bv1, &bv2);
        result             = result && (F64Abs(correlation - 1.0) < 0.001);

In Math.c:483:

        BitVecPush(&bv2, true);
    
        correlation = BitVecCorrelation(&bv1, &bv2);
        result      = result && (F64Abs(correlation + 1.0) < 0.001);

In Math.c:496:

        DefaultAllocator alloc = DefaultAllocatorInit();
    
        WriteFmt("Testing BitVecCorrelation edge cases\n");
    
        BitVec bv1    = BitVecInit(ALLOCATOR_OF(&alloc));

In Math.c:503:

    
        // Test empty bitvectors
        double correlation = BitVecCorrelation(&bv1, &bv2);
        result             = result && (correlation == 1.0);

In Math.c:514:

        BitVecPush(&bv2, true);
    
        correlation = BitVecCorrelation(&bv1, &bv2);
        result      = result && (correlation == 0.0); // No variance

In Math.c:726:

        double cosine      = BitVecCosineSimilarity(&bv1, &bv2);
        u64    dot_prod    = BitVecDotProduct(&bv1, &bv2);
        double correlation = BitVecCorrelation(&bv1, &bv2);
        double entropy1    = BitVecEntropy(&bv1);
        int    align_score = BitVecAlignmentScore(&bv1, &bv2, 1, -1);

In Math.c:887:

        DefaultAllocator alloc = DefaultAllocatorInit();
    
        WriteFmt("Testing BitVecCorrelation(NULL, bv2) - should fatal\n");
        BitVec bv2 = BitVecInit(ALLOCATOR_OF(&alloc));
        BitVecPush(&bv2, true);

In Math.c:890:

        BitVec bv2 = BitVecInit(ALLOCATOR_OF(&alloc));
        BitVecPush(&bv2, true);
        BitVecCorrelation(NULL, &bv2);
        BitVecDeinit(&bv2);
        DefaultAllocatorDeinit(&alloc);

In Math.c:899:

        DefaultAllocator alloc = DefaultAllocatorInit();
    
        WriteFmt("Testing BitVecCorrelation(bv1, NULL) - should fatal\n");
        BitVec bv1 = BitVecInit(ALLOCATOR_OF(&alloc));
        BitVecPush(&bv1, true);

In Math.c:902:

        BitVec bv1 = BitVecInit(ALLOCATOR_OF(&alloc));
        BitVecPush(&bv1, true);
        BitVecCorrelation(&bv1, NULL);
        BitVecDeinit(&bv1);
        DefaultAllocatorDeinit(&alloc);

In Math.c:1259:

        DefaultAllocator alloc = DefaultAllocatorInit();
    
        WriteFmt("Testing BitVecCorrelation with bv1 shorter than bv2 (no OOB)\n");
    
        BitVec bv1    = BitVecInit(ALLOCATOR_OF(&alloc));

In Math.c:1274:

        BitVecPush(&bv2, false);
    
        double correlation = BitVecCorrelation(&bv1, &bv2);
        result             = result && (correlation >= -1.0 && correlation <= 1.0);

In Math.c:1289:

        DefaultAllocator alloc = DefaultAllocatorInit();
    
        WriteFmt("Testing BitVecCorrelation with bv2 shorter than bv1 (no OOB)\n");
    
        BitVec bv1    = BitVecInit(ALLOCATOR_OF(&alloc));

In Math.c:1304:

        BitVecPush(&bv2, false);
    
        double correlation = BitVecCorrelation(&bv1, &bv2);
        result             = result && (correlation >= -1.0 && correlation <= 1.0);

Last updated on July 1, 2026

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