Tolerance is a distance value within which all nodes and/or lines are considered coincident or identical. This parameter needs to be configured when performing operations such as vector dataset processing, dynamic segmentation, and spatial analysis.

Default tolerance values vary across coordinate systems: For projected coordinate system source datasets, the default tolerance is 1m; For geographic coordinate system source datasets, the default tolerance is 0.00001°; For planar coordinate system source datasets, the default tolerance is one-millionth of the dataset's longest side length, with units matching the coordinate system's unit.

The default tolerance uses 1 meter as the baseline. For geographic coordinate system datasets (measured in degrees), the meter-to-degree conversion is based on Earth's circumference: The equatorial circumference is 40,075.7 km. Dividing 360° by 40,075.7 km yields approximately 0.0000898°/m. The actual degree value per meter increases at higher latitudes since the corresponding parallel circumference decreases. Therefore, 0.00001° is adopted as an approximate representation of 1 meter.

Notes:

• If the source vector dataset contains fuzzy tolerance, the default tolerance will match the fuzzy value.
• The valid range for tolerance is [0, +∞). Input values outside this range will trigger a red alert indicator before the input field.