Tolerance

class compas.tolerance.Tolerance

Bases: Data

Tolerance settings for geometric operations.

Parameters:

unit{“M”, “MM”}, optional

The unit of the tolerance settings.

namestr, optional

The name of the tolerance settings.

Attributes:

unit{“M”, “MM”}

The unit of the tolerance settings.

absolutefloat

The absolute tolerance.

relativefloat

The relative tolerance.

angularfloat

The angular tolerance.

approximationfloat

The tolerance used in approximation processes.

precisionint

The precision used when converting numbers to strings. Positive numbers correspond to the number of digits after the decimal point. Negative numbers correspond to the number of digits before the decimal point. Zero corresponds to integer precision. Therefore, the higher the number the higher the precision.

lineardeflectionfloat

The maximum distance between a curve or surface and its polygonal approximation.

Notes

The absolute tolerance is used to determine when a number is small enough to be considered zero. The relative tolerance determines the allowable deviation between two values for the values to be considered equal. The relative tolerance is defined as a fraction of one of the two values. This value is called the “true value”. By convention, the second value is considered the “true value” by the comparison functions of this class.

The compas.tolerance.Tolerance class is implemented using a “singleton” pattern and can therefore have only 1 (one) instance per context. Usage of compas.tolerance.TOL outside of compas internals is therefore deprecated.

Examples

>>> tol = Tolerance()
>>> tol.unit
'M'
>>> tol.absolute
1e-09
>>> tol.relative
1e-06
>>> tol.angular
1e-06

Methods

compare	Compare two values.
format_number	Format a number as a string.
geometric_key	Compute the geometric key of a point.
geometric_key_xy	Compute the geometric key of a point in the XY plane.
is_allclose	Check if two lists of values are element-wise close enough to be considered equal.
is_angle_zero	Check if an angle is close enough to zero to be considered zero.
is_angles_close	Check if two angles are close enough to be considered equal.
is_between	Check if a value is between two other values.
is_close	Check if two values are close enough to be considered equal.
is_negative	Check if a value can be considered a strictly negative number.
is_positive	Check if a value can be considered a strictly positive number.
is_zero	Check if a value is close enough to zero to be considered zero.
precision_from_tolerance	Compute the precision from a given tolerance.
reset	Reset all precision settings to their default values.
tolerance	Compute the tolerance for a comparison.
update_from_dict	Update the tolerance singleton from the key-value pairs found in a dict.

Inherited Methods

ToString	Converts the instance to a string.
copy	Make an independent copy of the data object.
from_json	Construct an object of this type from a JSON file.
from_jsonstring	Construct an object of this type from a JSON string.
sha256	Compute a hash of the data for comparison during version control using the sha256 algorithm.
to_json	Convert an object to its native data representation and save it to a JSON file.
to_jsonstring	Convert an object to its native data representation and save it to a JSON string.
validate_data	Validate the data against the object's data schema.