Function _MatrixBandPart

express/NeuralNetWorkOp.cpp:1107–1112

Copies a variable setting everything outside a central band in each innermost matrix. Arguments: input: Rank k variable. num_lower: Number of subdiagonals to keep. If negative, keep entire lower triangle. num_upper: Number of superdiagonals to keep. If negative, keep entire upper triangle. Returns: Output: Rank k variable of the same shape as input. The extracted banded tensor. */

Output: Rank k variable of the same shape as input. The extracted banded tensor.
*/
VARP _MatrixBandPart(VARP input, VARP num_lower, VARP num_upper) {
    std::unique_ptr<OpT> op(new OpT);
    op->type       = OpType_MatrixBandPart;
    op->main.type = OpParameter_NONE;
    return (Variable::create(Expr::create(std::move(op), {input, num_lower, num_upper})));
}
/*Calculates the mean and variance of x.
Args:
x: A variable. must be 4-D with NC4HW4 format.