Coord¶

Main Classes¶

Most classes in this module are collections.namedtuple objects.

Class	Description	Attributes
`Dim`	Linear dimension	value units
`Box`	A Box	width depth
`Pad`	Padding around a tree object	prev next, parent child
`Margin`	Padding around an object	left right top bottom
`Pt`	A point in Cartesian space	x y

Reference¶

exception cpip.plot.Coord.ExceptionCoord¶: Exception class for representing Coordinates.

exception cpip.plot.Coord.ExceptionCoordUnitConvert¶: Exception raised when converting units.

cpip.plot.Coord.BASE_UNITS = 'px'¶: Base units

cpip.plot.Coord.UNIT_MAP = {'pc': 12.0, None: 1.0, 'mm': 2.834645669291339, 'px': 1.0, 'in': 72.0, 'cm': 28.346456692913385, 'pt': 1.0}¶: Map of conversion factors, base unit is pixels.

cpip.plot.Coord.UNIT_MAP_DEFAULT_FORMAT = {'pc': '%.2f', None: '%d', 'mm': '%.1f', 'px': '%d', 'in': '%.3f', 'cm': '%.2f', 'pt': '%d'}¶: Formatting strings for writing attributes. We are trying not to write 3.999999999mm here!

cpip.plot.Coord.UNIT_MAP_DEFAULT_FORMAT_WITH_UNITS = {'pc': '%.2f%s', None: '%d%s', 'mm': '%.1f%s', 'px': '%d%s', 'in': '%.3f%s', 'cm': '%.2f%s', 'pt': '%d%s'}¶: Map of formatting strings for value and units e.g. to create ‘0.667in’ from (2.0 / 3.0, ‘in’)

cpip.plot.Coord.units()¶: Returns the unsorted list of acceptable units.

cpip.plot.Coord.convert(val, unitFrom, unitTo)¶

Convert a value from one set of units to another.

Parameters:	val (`float, int`) – The value unitFrom (`NoneType, str`) – The initial units. unitTo (`str`) – The new units.
Returns:	`float,int` – The value in the new units.

class cpip.plot.Coord.Dim¶

Represents a dimension as an engineering value i.e. a number and units.

scale(factor)¶: Returns a new Dim() scaled by a factor, units are unchanged.

convert(u)¶: Returns a new Dim() with units changed and value converted.

__add__(other)¶: Overload self+other, returned result has the sum of self and other. The units chosen are self’s unless self’s units are None in which case other’s units are used (if not None).

__sub__(other)¶: Overload self-other, returned result has the difference of self and other. The units chosen are self’s unless self’s units are None in which case other’s units are used (if not None).

__iadd__(other)¶: Addition in place, value of other is converted to my units and added.

__isub__(other)¶: Subtraction in place, value of other is subtracted.

__lt__(other)¶: Returns true if self value < other value after unit conversion.

__le__(other)¶: Returns true if self value <= other value after unit conversion.

__eq__(other)¶: Returns true if self value == other value after unit conversion.

__ne__(other)¶: Returns true if self value != other value after unit conversion.

__gt__(other)¶: Returns true if self value > other value after unit conversion.

__ge__(other)¶: Returns true if self value >= other value after unit conversion.

class cpip.plot.Coord.Pad¶

Padding around another object that forms the Bounding Box. All 4 attributes are Dim() objects

__str__()¶: Stringifying.

class cpip.plot.Coord.Pt¶

A point, an absolute x/y position on the plot area. Members are Coord.Dim().

__eq__(other)¶: Comparison.

__str__()¶: Stringifying.

convert(u)¶: Returns a new Pt() with units changed and value converted.

scale(factor)¶: Returns a new Pt() scaled by a factor, units are unchanged.

cpip.plot.Coord.baseUnitsDim(theLen)¶

Returns a Coord.Dim() of length and units BASE_UNITS.

Parameters:	theLen (`float, int`) – Length.
Returns:	`cpip.plot.Coord.Dim([float, str])` – A new dimension of theLen in base units.

cpip.plot.Coord.zeroBaseUnitsDim()¶

Returns a Coord.Dim() of zero length and units BASE_UNITS.

Returns:	`cpip.plot.Coord.Dim([float, str])` – A new dimension of zero.

cpip.plot.Coord.zeroBaseUnitsBox()¶: Returns a Coord.Box() of zero dimensions and units BASE_UNITS.

cpip.plot.Coord.zeroBaseUnitsPad()¶: Returns a Coord.Pad() of zero dimensions and units BASE_UNITS.

cpip.plot.Coord.zeroBaseUnitsPt()¶

Returns a Coord.Dim() of zero length and units BASE_UNITS.

Returns:	`cpip.plot.Coord.Pt([cpip.plot.Coord.Dim([float, str]), cpip.plot.Coord.Dim([float, str])])` – A new point with the values [0, 0].

cpip.plot.Coord.newPt(theP, incX=None, incY=None)¶

Returns a new Pt object by incrementing existing point incX, incY that are both Dim() objects or None.

Parameters:

theP (cpip.plot.Coord.Pt([cpip.plot.Coord.Dim([float, str]), cpip.plot.Coord.Pt([cpip.plot.Coord.Dim([float, str])])) – The initial point.
incX (NoneType, cpip.plot.Coord.Dim([float, str]), cpip.plot.Coord.Dim([int, str])) – Distance to move in the x axis.
incY (NoneType, cpip.plot.Coord.Dim([float, str]), cpip.plot.Coord.Dim([int, str])) – Distance to move in the y axis.

Returns:

cpip.plot.Coord.Pt([cpip.plot.Coord.Dim([float, str]), cpip.plot.Coord.Dim([float, str])]) – The new point.

cpip.plot.Coord.convertPt(theP, theUnits)¶

Returns a new point with the dimensions of theP converted to theUnits.

TODO: Deprecate this.

Examples¶

`Coord.Dim()`¶

Creation, addition and subtraction:

d = Coord.Dim(1, 'in') + Coord.Dim(18, 'px')
# d is 1.25 inches
d = Coord.Dim(1, 'in') - Coord.Dim(18, 'px')
# d is 0.75 inches
d += Coord.Dim(25.4, 'mm')
# d is 1.75 inches

Scaling and unit conversion returns a new object:

a = Coord.Dim(12, 'px')
b = myObj.scale(6.0)
# b is 72 pixels
c = b.convert('in')
# 1 is 1 inch

Comparison:

assert(Coord.Dim(1, 'in') == Coord.Dim(72, 'px'))
assert(Coord.Dim(1, 'in') >= Coord.Dim(72, 'px'))
assert(Coord.Dim(1, 'in') <= Coord.Dim(72, 'px'))
assert(Coord.Dim(1, 'in') > Coord.Dim(71, 'px'))
assert(Coord.Dim(1, 'in') < Coord.Dim(73, 'px'))

`Coord.Pt()`¶

Creation:

p = Coord.Pt(
        Coord.Dim(12, 'px'),
        Coord.Dim(24, 'px'),
        )
print(p)
# Prints: 'Pt(x=Dim(12px), y=Dim(24px))'
p.x # Coord.Dim(12, 'px'))
p.y # Coord.Dim(24, 'px'))
# Scale up by 6 and convert units
pIn = p.scale(6).convert('in')
# pIn now 'Pt(x=Dim(1in), y=Dim(2in))'

Testing¶

The unit tests are in test/TestCoord.py.