Spatial Information & Coordinates

Coordinates

Modes | Coord System

To determine points of reference in the graphics editor, usually for specifying distances or angles, it is necessary to use either an Absolute or Relative coordinate input method.

Coordinate entry is also used for relocating objects in the graphics editor by specifying a destination point which is relative in coordinate measurement to the source point.

Spatial information is input according to either a Polar or Rectangular coordinate system. Rectangular coordinates are also referred to as Cartesian coordinates.

Polar Coordinates

Polar coordinates are used to input Length and Angular measurements based on the coordinate position within a 360º circle shown below.

The formula for supplying a polar coordinate is Length, Angle. These coordinates are based on positive measurements.

Polar coordinates are calculated using the degrees of a circle, starting from east 3 o’clock as the 0° and moving anti-clockwise around the circle.

Polar angles shown in degrees

For example to draw the line shown below to a length of 50 and in the direction indicated by the arrow, the Length/Angle input would be Length = 50; Angle 30.

Line length = 50; Angle = 30

To draw the line shown below to a length of 50 and in the direction indicated by the arrow, the Length/Angle input would be Length = 50; Angle 210.

Line length = 50; Angle = 210

Rectangular Coordinates

Rectangular coordinates are defined by positive or negative X-Y values.

Rectangular coordinates are sometimes referred to as Cartesian coordinates.

Lines that travel in a straight line from left to right have positive x values.

Lines that travel in a straight line from right to left have negative x values.

Lines that travel from bottom to top have positive y values.

Lines that travel from top to bottom have negative y values.

Absolute Coordinates

Modes | Coord System | Relative

Absolute coordinates determine spatial distances based on the 0,0 origin position in the graphics editor.

All points drawn in the graphics editor are then referenced from this 0,0 base position.

The 0,0 base position is referred to as the Origin.

The origin can be relocated to any position in the graphics editor using Modes > Coord System > Relocate Origin.

Relative Coordinates

Modes | Coord System | Relative

This system of coordinates always moves the origin of 0,0 to the last indicated position in the graphics editor.

This means the calculation of the next point always assumes the last position was 0,0.

When using Relative Coordinate input, a red dot is always displayed at the last point indicated in the graphics editor. This point will always be 0,0.

Point indicates 0,0 position. Coordinate point of next line calculated from this.

Relocate Origin

Modes | Coord System | Relocate Origin

By relocating the origin in the graphics editor, all subsequent measurements are calculated from this point when using Relative coordinates.

Fixed Relative Origin

Options | Advanced Preferences | Fixed Relative Origin

A Fixed Relative Origin point can be given when the new origin is required to remain static for the duration of a task. This is done using Options > Preferences > Fixed Relative Origin. All points are subsequently calculated from this fixed point until this option is removed.

Use Options | Advanced Preferences to create a Fixed Relative Origin