nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/indexing/BooleanIndexing.java
public static void applyWhere(final INDArray to, final Condition condition, final Number number) {
        if (condition instanceof BaseCondition) {
            // for all static conditions we go native

            Nd4j.getExecutioner().exec(new CompareAndSet(to, number.doubleValue(), condition));

        } else {
            final double value = number.doubleValue();

            final Function<Number, Number> dynamic = new Function<Number, Number>() {
                @Override
                public Number apply(Number number) {
                    return value;
                }
            };

            Shape.iterate(to, new CoordinateFunction() {
                @Override
                public void process(long[]... coord) {
                    if (condition.apply(to.getDouble(coord[0])))
                        to.putScalar(coord[0], dynamic.apply(to.getDouble(coord[0])).doubleValue());

                }
            });
        }
    }
public static void applyWhere(final INDArray to, final Condition condition, final Number number) {
        if (condition instanceof BaseCondition) {
            // for all static conditions we go native

            Nd4j.getExecutioner().exec(new CompareAndSet(to, number.doubleValue(), condition));

        } else {
            final double value = number.doubleValue();

            final Function<Number, Number> dynamic = new Function<Number, Number>() {
                @Override
                public Number apply(Number number) {
                    return value;
                }
            };

            Shape.iterate(to, new CoordinateFunction() {
                @Override
                public void process(long[]... coord) {
                    if (condition.apply(to.getDouble(coord[0])))
                        to.putScalar(coord[0], dynamic.apply(to.getDouble(coord[0])).doubleValue());

                }
            });
        }
    }
This method sets provided number to all elements which match specified condition

@param to
@param condition
@param number