Orthogonalize

The Orthogonalize command moves coordinates to orthogonal grid positions at the specified X and Y grid steps. The command is used mainly to trim insignificant digits from coordinates. For example, suppose we are working with a projected data set expressed in meter-based coordinates and we know that our data set is only accurate within 10 meters. In such cases, there is only an illusion of accuracy when using coordinates such as 34592.490593845 meters. It may as well be 34590 meters. If every coordinate were moved to the nearest ten-meter coordinate position, we would achieve the effect of rounding all coordinates. Orthogonalize command performs exactly this function.

 

images\dlg_orthogonalize.gif

 

 

Scope

The set of objects to alter.

Steps

The X and Y dimensions of the grid cells.

Offsets

The X and Y offsets of a grid cell that may be used.

 

Offsets are combined with Steps to nudge the orthogonalization in desired X and/or Y directions. With X and Y Steps equal to 100 using zero Offsets will force the coordinates of objects to the nearest locations on a 100 x 100 grid of cells (for example, 0:0, 100:0, 0:100, ...).

 

With X and Y Steps equal to 100 using Offsets of 10 and 20 will force the coordinates of objects to the nearest locations on a 100 x 100 grid that is shifted in both horizontal and vertical directions by 10 and 20 units (for example, 10:20, 110:20, 10:120, ...).

 

Example

 

images\sc_orthogonalize_01.gif

 

Suppose we start with a drawing of Durango province in Mexico using Orthographic projection.

 

images\sc_orthogonalize_02.gif

 

After applying the Orthogonalize command with X and Y steps of 25000 meters the province takes on a distinctly stair-step appearance as coordinates are forced to the nearest 25000-meter grid position. The Orthogonalize command is not normally used in cases where the original coordinates appear in much finer resolution than the steps specified, so some regions have been collapsed into topologically redundant appendages. These can be fixed by running the Normalize Topology transform toolbar operator.

 

images\sc_orthogonalize_03.gif

 

The Normalize topology operator cleans up the topology.