While using the Commander to insert or edit elements, you may choose to work in the Cartesian coordinate system instead of the Polar coordinate system. This lets you specify a precise reference point to draw or move from by entering X, Y and Z coordinate values.
X. Enter an X coordinate to specify a horizontal (left/right) distance in 2D plan view.
Y. Enter a Y coordinate to specify a vertical (up/down) distance in 2D plan view.
Z. Enter a Z coordinate to indicate elevation, or height. If the element is a building element, the Z value is measured from the floor level of the current building location. If the element is a landscape element, the Z value is measured from the terrain.
Remember that the coordinates are measured from the current reference point, which is marked by the Coordinate Icon.
In the Cartesian system, you can enter both positive and negative values for any of the coordinates.