@SuppressWarnings("fallthrough")
    public void set(int i, int j, float value) {
        switch (i) {
            case 0:
                switch (j) {
                    case 0:
                        m00 = value;
                        return;
                    case 1:
                        m01 = value;
                        return;
                    case 2:
                        m02 = value;
                        return;
                    case 3:
                        m03 = value;
                        return;
                }
            case 1:
                switch (j) {
                    case 0:
                        m10 = value;
                        return;
                    case 1:
                        m11 = value;
                        return;
                    case 2:
                        m12 = value;
                        return;
                    case 3:
                        m13 = value;
                        return;
                }
            case 2:
                switch (j) {
                    case 0:
                        m20 = value;
                        return;
                    case 1:
                        m21 = value;
                        return;
                    case 2:
                        m22 = value;
                        return;
                    case 3:
                        m23 = value;
                        return;
                }
            case 3:
                switch (j) {
                    case 0:
                        m30 = value;
                        return;
                    case 1:
                        m31 = value;
                        return;
                    case 2:
                        m32 = value;
                        return;
                    case 3:
                        m33 = value;
                        return;
                }
        }

        logger.warning("Invalid matrix index.");
        throw new IllegalArgumentException("Invalid indices into matrix.");
    }
Store the specified value at the specified position.

@param i the row index of the element to set (0, 1, 2, or 3)
@param j the column index of the element to set (0, 1, 2, or 3)
@param value the value for element (i, j)
@throws IllegalArgumentException if either index is invalid.
jme3-core/src/main/java/com/jme3/math/Matrix4f.java