This topic documents the concept of applying precision and rounding.
Co-ordinates, elevations, bearings, distances and areas are displayable to either a user specified precision or rounding. Volumes are always displayed according to the precision setting.
The precision setting for a particular type of dimension is applied to all dimensions of that type, where as, rounding is an attribute held independently with each dimension.
For example, at any instant, all distances have the same precision, whereas each individual distance may have its own rounding attribute.
Precision
The precision settings govern the number of places to which dimensions are displayed to the user when they are examined.
Dimensions are also displayed in the graphics window according to their precision settings if a rounding attribute is not set or if rounded display is not active. If rounded display is active, then the dimensions are displayed according to their individual rounding attributes.
Note that dimensions are stored or computed in the data base to full accuracy. Setting a precision to a certain number of places does not change the accuracy to which values are computed or stored. It merely provides a means of displaying them to a certain number of places.
Precision may be independently set for each of the following types of dimensions:
Grid Co-ordinates
Geographical Co-ordinates
Elevations
Bearings includes plane, azimuth, and grid bearings, and polygon angles.
Distances includes plane ellipsoidal and ground distances.
Areas
Volumes
For example, setting the elevation precision to two decimal places means that all elevations in the data base will be displayed to 2 decimal places unless rounding is active.
Note however that the precision settings may be changed at any time and reflected in the display.
Rounding
The rounding attributes govern the number of places to which each dimension is displayed in the graphics window if rounded display is active. If rounded display is not active, then the dimensions are displayed according to the precision.
Note that dimensions are stored in the data base to full accuracy. Setting a rounding attribute of a certain number of places does not change the accuracy to which the value is computed or stored. It merely provides a means of displaying the dimension to a certain number of places.
Three different rounding definitions (1, 2, and 3) may be independently defined for each of the following types of dimensions:
Grid Co-ordinates
Elevations
Angles (Bearings) includes plane, azimuth, and grid bearings, and polygon angles.
Distances includes plane and ellipsoidal distances.
Areas
Each individual dimension has a rounding attribute which can be set to 0, 1, 2, or 3. If the attribute is zero, then rounding cannot be applied to that dimension. If the attribute is 1, 2 or 3, then the dimension's rounding is defined by the corresponding rounding definition.
For example, an elevation with a rounding attribute set to 2 will be rounded according to the elevation rounding definition 2.
The rounding attribute of a dimension or the rounding definitions may be changed at any time and reflected in the display.
For further help on precision and rounding, select from the following topics.
See Also
| Utilities/Configure/ | Co-ordinates |
| Angles | |
| Distances | |
| Areas | |
| Volumes | |
| (for setting precision and rounding definitions) |
Computations/Attribute (for setting rounding attributes)
Computations/Edit/View-Edit Point (for changing rounding attributes)
Display/Features Rounding check box (for displaying dimensions according to their rounding attributes)