Java Code Examples for org.nd4j.linalg.api.ndarray.INDArray#offset()

/** Tensor1DStats, used to efficiently iterate through tensors on a matrix (2d NDArray) for element-wise ops
 * For example, the offset of each 1d tensor can be calculated using only a single tensorAlongDimension method call,
 * hence is potentially faster than approaches requiring multiple tensorAlongDimension calls.<br>
 * Note that this can only (generally) be used for 2d NDArrays. For certain 3+d NDArrays, the tensor starts may not
 * be in increasing order
 */
public static Tensor1DStats get1DTensorStats(INDArray array, int... dimension) {
    long tensorLength = array.size(dimension[0]);

    //As per tensorssAlongDimension:
    long numTensors = array.tensorssAlongDimension(dimension);

    //First tensor always starts with the first element in the NDArray, regardless of dimension
    long firstTensorOffset = array.offset();

    //Next: Need to work out the separation between the start (first element) of each 1d tensor
    long tensorStartSeparation;
    int elementWiseStride; //Separation in buffer between elements in the tensor
    if (numTensors == 1) {
        tensorStartSeparation = -1; //Not applicable
        elementWiseStride = array.elementWiseStride();
    } else {
        INDArray secondTensor = array.tensorAlongDimension(1, dimension);
        tensorStartSeparation = secondTensor.offset() - firstTensorOffset;
        elementWiseStride = secondTensor.elementWiseStride();
    }

    return new Tensor1DStats(firstTensorOffset, tensorStartSeparation, numTensors, tensorLength, elementWiseStride);
}
 

private String shapeInfo(INDArray arr) {
    return Arrays.toString(arr.shape()) + " and stride " + Arrays.toString(arr.stride()) + " and offset "
                    + arr.offset() + " and blas stride of " + BlasBufferUtil.getBlasStride(arr);
}
 

private INDArray copyIfNecessaryVector(INDArray vec) {
    if (vec.offset() != 0)
        return vec.dup();
    return vec;
}
 

public static boolean checkGemm(INDArray a, INDArray b, INDArray c, boolean transposeA, boolean transposeB,
                double alpha, double beta, double maxRelativeDifference, double minAbsDifference) {
    long commonDimA = (transposeA ? a.rows() : a.columns());
    long commonDimB = (transposeB ? b.columns() : b.rows());
    if (commonDimA != commonDimB)
        throw new IllegalArgumentException("Common dimensions don't match: a.shape=" + Arrays.toString(a.shape())
                        + ", b.shape=" + Arrays.toString(b.shape()) + ", tA=" + transposeA + ", tb=" + transposeB);
    long outRows = (transposeA ? a.columns() : a.rows());
    long outCols = (transposeB ? b.rows() : b.columns());
    if (c.rows() != outRows || c.columns() != outCols)
        throw new IllegalArgumentException("C does not match outRows or outCols");
    if (c.offset() != 0 || c.ordering() != 'f')
        throw new IllegalArgumentException("Invalid c");

    INDArray aConvert = transposeA ? a.transpose() : a;
    RealMatrix rmA = convertToApacheMatrix(aConvert);
    INDArray bConvet = transposeB ? b.transpose() : b;
    RealMatrix rmB = convertToApacheMatrix(bConvet);
    RealMatrix rmC = convertToApacheMatrix(c);
    RealMatrix rmExpected = rmA.scalarMultiply(alpha).multiply(rmB).add(rmC.scalarMultiply(beta));
    INDArray cCopy1 = Nd4j.create(c.shape(), 'f');
    cCopy1.assign(c);
    INDArray cCopy2 = Nd4j.create(c.shape(), 'f');
    cCopy2.assign(c);

    INDArray out = Nd4j.gemm(a, b, c, transposeA, transposeB, alpha, beta);
    if (out != c) {
        System.out.println("Returned different array than c");
        return false;
    }
    if (!checkShape(rmExpected, out))
        return false;
    boolean ok = checkEntries(rmExpected, out, maxRelativeDifference, minAbsDifference);
    if (!ok) {
        INDArray aCopy = Shape.toOffsetZeroCopy(a);
        INDArray bCopy = Shape.toOffsetZeroCopy(b);
        INDArray onCopies = Nd4j.gemm(aCopy, bCopy, cCopy1, transposeA, transposeB, alpha, beta);
        printGemmFailureDetails(a, b, cCopy2, transposeA, transposeB, alpha, beta, rmExpected, out, onCopies);
    }
    return ok;
}
 

private INDArray copyIfNecessaryVector(INDArray vec) {
    if (vec.offset() != 0)
        return vec.dup();
    return vec;
}
 

public static boolean checkGemm(INDArray a, INDArray b, INDArray c, boolean transposeA, boolean transposeB,
                double alpha, double beta, double maxRelativeDifference, double minAbsDifference) {
    long commonDimA = (transposeA ? a.rows() : a.columns());
    long commonDimB = (transposeB ? b.columns() : b.rows());
    if (commonDimA != commonDimB)
        throw new IllegalArgumentException("Common dimensions don't match: a.shape=" + Arrays.toString(a.shape())
                        + ", b.shape=" + Arrays.toString(b.shape()) + ", tA=" + transposeA + ", tb=" + transposeB);
    long outRows = (transposeA ? a.columns() : a.rows());
    long outCols = (transposeB ? b.rows() : b.columns());
    if (c.rows() != outRows || c.columns() != outCols)
        throw new IllegalArgumentException("C does not match outRows or outCols");
    if (c.offset() != 0 || c.ordering() != 'f')
        throw new IllegalArgumentException("Invalid c");

    INDArray aConvert = transposeA ? a.transpose() : a;
    RealMatrix rmA = convertToApacheMatrix(aConvert);
    INDArray bConvet = transposeB ? b.transpose() : b;
    RealMatrix rmB = convertToApacheMatrix(bConvet);
    RealMatrix rmC = convertToApacheMatrix(c);
    RealMatrix rmExpected = rmA.scalarMultiply(alpha).multiply(rmB).add(rmC.scalarMultiply(beta));
    INDArray cCopy1 = Nd4j.create(c.shape(), 'f');
    cCopy1.assign(c);
    INDArray cCopy2 = Nd4j.create(c.shape(), 'f');
    cCopy2.assign(c);

    INDArray out = Nd4j.gemm(a, b, c, transposeA, transposeB, alpha, beta);
    if (out != c) {
        System.out.println("Returned different array than c");
        return false;
    }
    if (!checkShape(rmExpected, out))
        return false;
    boolean ok = checkEntries(rmExpected, out, maxRelativeDifference, minAbsDifference);
    if (!ok) {
        INDArray aCopy = Shape.toOffsetZeroCopy(a);
        INDArray bCopy = Shape.toOffsetZeroCopy(b);
        INDArray onCopies = Nd4j.gemm(aCopy, bCopy, cCopy1, transposeA, transposeB, alpha, beta);
        printGemmFailureDetails(a, b, cCopy2, transposeA, transposeB, alpha, beta, rmExpected, out, onCopies);
    }
    return ok;
}
 

/**
 * Get blas stride for the
 * given array
 * @param arr the array
 * @return the blas stride
 */
public static int getBlasOffset(INDArray arr) {
    // FIXME: LONG
    return (int) arr.offset();
}
 

/**
 * Get blas stride for the
 * given array
 * @param arr the array
 * @return the blas stride
 */
public static long getBlasOffset(INDArray arr) {
    return arr.offset();
}