nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/ops/transforms/Transforms.java
public static INDArray hardTanh(INDArray ndArray, boolean dup) {
        return exec(dup ? new HardTanh(ndArray, ndArray.dup()) : new HardTanh(ndArray));
    }
public static INDArray hardTanh(INDArray ndArray, boolean dup) {
        return exec(dup ? new HardTanh(ndArray, ndArray.dup()) : new HardTanh(ndArray));
    }
Hard tanh

@param ndArray the input
@param dup     whether to duplicate the ndarray and return it as the result
@return the output