Measurements & Fit Classes¶

`sewpat.measurements` ¶

Ease-adjusted garment measurements derived from body measurements and fit class.

This module provides dataclasses for garment measurements (with ease already applied), distribution helpers that split waist and hip shortfall into darts and side-seam intakes, and factory functions that combine a :class:~sewpat.person.Person with a :class:~sewpat.fitclass.FitClass to produce construction-ready measurements.

`BlouseMeasurements(bust: float, waist: float, hip: float, hip_depth: float, bust_depth: float, neck_size: float, bust_span: float, shoulder_width: float, back_length: float, front_length: float, bust_width: float, waist_width: float, hip_width: float, armscye_depth: float, back_width: float, armscye_width: float, chest_width: float, gender: Gender = Gender.FEMALE)` `dataclass` ¶

Ease-adjusted measurements for blouse / top construction.

All values are in mm (the project's internal unit). Build via :func:make_top_measurements from a :class:~sewpat.person.BalancedPerson and a :class:~sewpat.fitclass.FitClass.

Attributes:

Name	Type	Description
`bust`	`float`	BrU — Brustumfang (bust circumference).
`waist`	`float`	TaU — Taillenumfang (waist circumference).
`hip`	`float`	HüU — Hüftumfang (hip circumference).
`hip_depth`	`float`	HüT — Hüfttiefe (hip depth).
`bust_depth`	`float`	BrT — Brusttiefe (bust depth).
`neck_size`	`float`	HlB — Halslochbreite (neck hole width).
`bust_span`	`float`	BrPA — Brustpunktabstand (bust point distance).
`shoulder_width`	`float`	SuB — Schulterbreite (shoulder width, with ease).
`back_length`	`float`	RüL — Rückenlänge (back length).
`front_length`	`float`	VL — Vorderlänge (front length).
`bust_width`	`float`	BrW — Brustbreite fertig (half-width, with ease).
`waist_width`	`float`	TaW — Taillenweite fertig (half-width, with ease).
`hip_width`	`float`	HüW — Hüftweite fertig (half-width, with ease).
`armscye_depth`	`float`	AlT — Armlochtiefe (armhole depth, with ease).
`back_width`	`float`	RüB — Rückenbreite (back width, with ease).
`armscye_width`	`float`	ArD — Armdurchmesser (arm diameter, with ease).
`chest_width`	`float`	BrB — Brustbreite (chest width, with ease).
`gender`	`Gender`	Used for gender-specific construction formulas.

`__post_init__() -> None` ¶

Validate that back + armscye + chest widths sum to bust_width / 2.

`TrouserMeasurements(waist: float, hip: float, body_rise: float, waist_width: float, hip_width: float, hip_depth: float | None = None, inseam: float | None = None, sTaH: float | None = None, knee_height: float | None = None, front_trouser_width: float | None = None, gender: Gender = Gender.FEMALE)` `dataclass` ¶

Ease-adjusted measurements for trouser construction.

All values are in mm (the project's internal unit).

Attributes:

Name	Type	Description
`waist`	`float`	TaU — Taillenumfang (waist circumference, with ease).
`hip`	`float`	HüU — Hüftumfang (hip circumference, with ease).
`body_rise`	`float`	SiH — Sitzhöhe (body rise, with ease).
`waist_width`	`float`	TaW — Taillenweite fertig (finished waist half-width).
`hip_width`	`float`	HüW — Hüftweite fertig (finished hip half-width).
`hip_depth`	`float \| None`	HüT — Hüfttiefe (hip depth; optional).
`inseam`	`float \| None`	SrH — Schritthöhe (inside leg length; optional).
`sTaH`	`float \| None`	Combined rise + inseam for children (optional).
`knee_height`	`float \| None`	Kniehöhe (knee height, derived if not given).
`front_trouser_width`	`float \| None`	vHoB — Vorderhosenbreite (defaults to 25 % of hip_width).
`gender`	`Gender`	Used for gender-specific construction formulas.

`__post_init__() -> None` ¶

Derive front_trouser_width and knee_height when not explicitly set.

`TrouserEase(body_rise_ease: float = 0.0, inseam_ease: float = 0.0, hip_ease: float = 0.0, waist_ease: float = 0.0)` `dataclass` ¶

Explicit ease additions for trouser construction.

Used when no fit-class PK table entry is available for the garment type (e.g. children's shorts, sportswear). All values in mm.

Attributes:

Name	Type	Description
`body_rise_ease`	`float`	Added to body rise (SiH).
`inseam_ease`	`float`	Added to inside-leg length (SrH).
`hip_ease`	`float`	Added to hip circumference (HüU).

`GarmentConfig(length: float, seam_allowance: float = 1 * CM, hem_width: float | None = None, shoulder_gather: float = 1 * CM, armscye_fit: float = 0.0, waist_dart_back_tip: float = 16 * CM, waist_dart_front_tip: float = 12 * CM, side_seam_intake_max: float = 2 * CM)` `dataclass` ¶

Pure garment-design choices — independent of body measurements and fit.

Attributes:

Name	Type	Description
`length`	`float`	Modell-Länge (MoL) — finished garment length (hem to nape).
`seam_allowance`	`float`	Nahtzugabe — seam allowance width added to all seams.
`hem_width`	`float \| None`	Saumweite (SaW) — hem width (optional; used for trousers).
`shoulder_gather`	`float`	Schulter-Weite — gather/ease added to the shoulder seam length. Lengthens the shoulder seam on both pieces so fabric can be eased or gathered at the sleeve head.
`armscye_fit`	`float`	Controls how tightly the front armscye fits around the upper arm. Range 0–1 cm: 0 = regular fit, 1 = tight fit. Shifts the front armscye shoulder point inward, reducing the armhole circumference.
`waist_dart_back_tip`	`float`	Distance from the waist dart centre to its lower (hem-side) tip on the back piece. Range: 13–16 cm.
`waist_dart_front_tip`	`float`	Distance from the waist dart centre to its lower (hem-side) tip on the front piece.
`side_seam_intake_max`	`float`	Maximum side-seam intake per side used when distributing the waist shortfall. Default 2 cm (fitted/waisted-dart block). Set to 0–1 cm for a casual block where shaping is achieved by the side seam alone, without waist darts.

`__post_init__() -> None` ¶

Validate armscye_fit and waist_dart_back_tip are within permitted ranges.

`TrouserConfig(length: float, seam_allowance: float = 1 * CM, hem_width: float | None = None, shoulder_gather: float = 1 * CM, armscye_fit: float = 0.0, waist_dart_back_tip: float = 16 * CM, waist_dart_front_tip: float = 12 * CM, side_seam_intake_max: float = 2 * CM, front_trouser_ease: float | None = None)` `dataclass` ¶

Bases: GarmentConfig

Garment-design choices specific to trousers.

Attributes:

Name	Type	Description
`front_trouser_ease`	`float \| None`	Zugabe vordere Hosenbreite (ZuvHoB).

`HipDistribution(front_hip_width: float, back_hip_width: float, total_hip_width: float, hip_shortfall: float)` `dataclass` ¶

Result of the hip excess / shortfall (Fehlbetrag) calculation.

All values are in the project's internal unit (mm).

Attributes:

Name	Type	Description
`front_hip_width`	`float`	Distance from center-front to side-seam at hip level.
`back_hip_width`	`float`	Distance from side-seam to center-back at hip level.
`total_hip_width`	`float`	Total hip width on the pattern (= front + back).
`hip_shortfall`	`float`	Hip excess = total_hip_width − hip_width / 2.

`WaistDistribution(front_waist_width: float, back_waist_width: float, total_waist_width: float, hip_shortfall: float, side_seam_intake: float, front_dart_width: float, back_dart_width: float, remainder: float)` `dataclass` ¶

Result of the waist-dart hip_shortfall (Ausfallbetrag) calculation.

All values are in the project's internal unit (mm).

Attributes:

Name	Type	Description
`front_waist_width`	`float`	Distance from center-front to side-seam at waist level.
`back_waist_width`	`float`	Distance from side-seam to center-back at waist level.
`total_waist_width`	`float`	Total waist width on the pattern (= front + back).
`hip_shortfall`	`float`	Waist excess = total_waist_width − waist_width / 2.
`side_seam_intake`	`float`	Side-seam take-in per side (clamped to 0–2 cm).
`front_dart_width`	`float`	Front waist dart intake (clamped to 1–3 cm).
`back_dart_width`	`float`	Back waist dart intake (clamped to 2–4 cm).
`remainder`	`float`	Undistributed excess after clamping (0 if perfectly distributed).

`make_top_measurements(person: BalancedPerson, fit_class: FitClass) -> BlouseMeasurements` ¶

Build ease-included top measurements from a balanced person and fit class.

Parameters:

Name	Type	Description	Default
`person`	`BalancedPerson`	A :class:`~sewpat.person.BalancedPerson` — use :meth:`~sewpat.person.PersonAnalyser.get_balanced_person` to obtain one.	required
`fit_class`	`FitClass`	:class:`~sewpat.fitclass.FitClass` providing all ease values.	required

`make_measurements_trouser(person: Person, ease: TrouserEase, balance: BalanceAdjustments | None = None) -> TrouserMeasurements` ¶

Build ease-included trouser measurements.

Parameters:

Name	Type	Description	Default
`person`	`Person`	Body measurements.	required
`ease`	`TrouserEase`	:class:`TrouserEase` with trouser-specific ease additions.	required
`balance`	`BalanceAdjustments \| None`	Optional front/back length corrections.	`None`

`calculate_hip_distribution(meas: BlouseMeasurements, pt_hip_cf: Point, pt_hip_sf: Point, pt_hip_sb: Point, pt_hip_cb: Point) -> HipDistribution` ¶

Calculate the hip excess / shortfall at the hip line.

Parameters:

Name	Type	Description	Default
`meas`	`BlouseMeasurements`	Blouse measurements (ease already included).	required
`pt_hip_cf`	`Point`	Intersection of center-front with hip line.	required
`pt_hip_sf`	`Point`	Intersection of side-front with hip line.	required
`pt_hip_sb`	`Point`	Intersection of side-back with hip line.	required
`pt_hip_cb`	`Point`	Intersection of center-back with hip line.	required

Returns:

Type	Description
`HipDistribution`	class:`HipDistribution` with all computed values.

`calculate_waist_distribution(meas: BlouseMeasurements, pt_waist_cf: Point, pt_waist_sf: Point, pt_waist_sb: Point, pt_waist_cb: Point, side_seam_intake_max: float = 2.0 * CM) -> WaistDistribution` ¶

Calculate how the waist hip_shortfall (Ausfallbetrag) is distributed to darts.

Measures the pattern distances at the waist line, computes the total excess over the finished waist measurement, and splits it between the two side seams and the front / back waist darts using rule-based clamping.

Parameters:

Name	Type	Description	Default
`meas`	`BlouseMeasurements`	Blouse measurements (ease already included).	required
`pt_waist_cf`	`Point`	Intersection of center-front with waist line.	required
`pt_waist_sf`	`Point`	Intersection of side-front with waist line.	required
`pt_waist_sb`	`Point`	Intersection of side-back with waist line.	required
`pt_waist_cb`	`Point`	Intersection of center-back with waist line.	required
`side_seam_intake_max`	`float`	Maximum side-seam intake per side (clamped upper bound). Default 2 cm (waisted/fitted block). Pass a smaller value (0–1 cm) for a casual block where no waist darts are used and shaping comes from the side seam only.	`2.0 * CM`

Returns:

Type	Description
`WaistDistribution`	class:`WaistDistribution` with all computed values.

`sewpat.fitclass` ¶

Fit class (Passformklasse) — single source of truth for garment ease.

The :class:FitClass wraps a single integer pk in the range 0–12 that encodes how tightly a garment fits the body. All ease values are read from src/sewpat/data/fitclass.csv (multi-index: pk × ease field × lo/hi).

Default values are the upper bound (hi) of the published range. Any field may be overridden at construction time; the value must lie within the published [lo, hi] range or a :class:ValueError is raised.

bust_point_ease (ZuBrA) is derived as a construction offset and is included in the table; bust_width_ease is never stored — it is always derived as 2 × (back_width_ease + armscye_width_ease + chest_width_ease).

Only PK 4 is populated with real values. All other PKs raise :class:KeyError until the full Mueller & Sohn table is digitised.

Typical PK ranges¶

0–3 Swimwear, underwear, bodysuits 4–7 Blouses, light dresses, fitted tops 8–11 Jackets, structured coats 12 Heavy coats

Source: Mueller & Sohn, Rundschau / Modenähen drafting system.

`FitClass(pk: int, back_width_ease: float | None = None, armscye_width_ease: float | None = None, chest_width_ease: float | None = None, armscye_depth_ease: float | None = None, waist_ease: float | None = None, hip_ease: float | None = None, bust_point_ease: float | None = None, shoulder_width_ease: float | None = None)` `dataclass` ¶

Fit class — single source of truth for ease and construction offsets.

Pass only pk to use upper-bound defaults for all ease fields. Override individual fields as needed; each must lie within the published range for the given PK or a :class:ValueError is raised.

bust_width_ease is always derived and cannot be set directly.

Parameters:

Name	Type	Description	Default
`pk`	`int`	Integer 0–12 describing garment fit tightness.	required
`back_width_ease`	`float \| None`	RüB — override in mm.	`None`
`armscye_width_ease`	`float \| None`	ArD — override in mm.	`None`
`chest_width_ease`	`float \| None`	BrB — override in mm.	`None`
`armscye_depth_ease`	`float \| None`	AlT — override in mm.	`None`
`waist_ease`	`float \| None`	TaU — override in mm.	`None`
`hip_ease`	`float \| None`	HüU — override in mm.	`None`
`bust_point_ease`	`float \| None`	ZuBrA — override in mm.	`None`
`shoulder_width_ease`	`float \| None`	ScB — override in mm.	`None`

Examples::

fc = FitClass(pk=4)                         # all upper-bound defaults
fc = FitClass(pk=4, back_width_ease=0.7*CM) # override one field
fc.back_width_ease                          # → resolved value (mm)
fc.bust_width_ease                          # → always derived

Initialise FitClass from pk with optional per-field ease overrides.

`armscye_depth_ease: float` `property` ¶

AlT — Armlochtiefe-Zugabe (override or table hi).

`armscye_width_ease: float` `property` ¶

ArD — Armdurchmesser-Zugabe (override or table hi).

`back_width_ease: float` `property` ¶

RüB — Rückenbreite-Zugabe (override or table hi).

`bust_point_ease: float` `property` ¶

ZuBrA — Zugabe Brustpunktabstand (override or table hi).

`bust_width_ease: float` `property` ¶

BrW-Zugabe — always derived: 2 × (back + armscye_width + chest).

`chest_width_ease: float` `property` ¶

BrB — Brustbreite-Zugabe (override or table hi).

`hip_ease: float` `property` ¶

HüU — Hüftumfang-Zugabe (override or table hi).

`shoulder_width_ease: float` `property` ¶

ScB — Schulterbreite-Zugabe (override or table hi).

`waist_ease: float` `property` ¶

TaU — Taillenumfang-Zugabe (override or table hi).

`__post_init__() -> None` ¶

Validate pk and resolve ease fields from the table.

`range(field_name: str) -> _Range` ¶

Return the published [lo, hi] range for field_name at this PK.

Parameters:

Name	Type	Description	Default
`field_name`	`str`	One of the names in :data:`EASE_FIELDS`.	required

Raises:

Type	Description
`KeyError`	if field_name is not a recognised ease field.

Measurements & Fit Classes¶

sewpat.measurements ¶

__post_init__() -> None ¶

__post_init__() -> None ¶

TrouserEase(body_rise_ease: float = 0.0, inseam_ease: float = 0.0, hip_ease: float = 0.0, waist_ease: float = 0.0) dataclass ¶

GarmentConfig(length: float, seam_allowance: float = 1 * CM, hem_width: float | None = None, shoulder_gather: float = 1 * CM, armscye_fit: float = 0.0, waist_dart_back_tip: float = 16 * CM, waist_dart_front_tip: float = 12 * CM, side_seam_intake_max: float = 2 * CM) dataclass ¶

__post_init__() -> None ¶

HipDistribution(front_hip_width: float, back_hip_width: float, total_hip_width: float, hip_shortfall: float) dataclass ¶

WaistDistribution(front_waist_width: float, back_waist_width: float, total_waist_width: float, hip_shortfall: float, side_seam_intake: float, front_dart_width: float, back_dart_width: float, remainder: float) dataclass ¶

make_top_measurements(person: BalancedPerson, fit_class: FitClass) -> BlouseMeasurements ¶

make_measurements_trouser(person: Person, ease: TrouserEase, balance: BalanceAdjustments | None = None) -> TrouserMeasurements ¶

calculate_hip_distribution(meas: BlouseMeasurements, pt_hip_cf: Point, pt_hip_sf: Point, pt_hip_sb: Point, pt_hip_cb: Point) -> HipDistribution ¶

calculate_waist_distribution(meas: BlouseMeasurements, pt_waist_cf: Point, pt_waist_sf: Point, pt_waist_sb: Point, pt_waist_cb: Point, side_seam_intake_max: float = 2.0 * CM) -> WaistDistribution ¶

sewpat.fitclass ¶

Typical PK ranges¶

armscye_depth_ease: float property ¶

armscye_width_ease: float property ¶

back_width_ease: float property ¶

bust_point_ease: float property ¶

bust_width_ease: float property ¶

chest_width_ease: float property ¶

hip_ease: float property ¶

shoulder_width_ease: float property ¶

waist_ease: float property ¶

__post_init__() -> None ¶

range(field_name: str) -> _Range ¶

`sewpat.measurements` ¶

`__post_init__() -> None` ¶

`__post_init__() -> None` ¶

`TrouserEase(body_rise_ease: float = 0.0, inseam_ease: float = 0.0, hip_ease: float = 0.0, waist_ease: float = 0.0)` `dataclass` ¶

`GarmentConfig(length: float, seam_allowance: float = 1 * CM, hem_width: float | None = None, shoulder_gather: float = 1 * CM, armscye_fit: float = 0.0, waist_dart_back_tip: float = 16 * CM, waist_dart_front_tip: float = 12 * CM, side_seam_intake_max: float = 2 * CM)` `dataclass` ¶

`__post_init__() -> None` ¶

`HipDistribution(front_hip_width: float, back_hip_width: float, total_hip_width: float, hip_shortfall: float)` `dataclass` ¶

`WaistDistribution(front_waist_width: float, back_waist_width: float, total_waist_width: float, hip_shortfall: float, side_seam_intake: float, front_dart_width: float, back_dart_width: float, remainder: float)` `dataclass` ¶

`make_top_measurements(person: BalancedPerson, fit_class: FitClass) -> BlouseMeasurements` ¶

`make_measurements_trouser(person: Person, ease: TrouserEase, balance: BalanceAdjustments | None = None) -> TrouserMeasurements` ¶

`calculate_hip_distribution(meas: BlouseMeasurements, pt_hip_cf: Point, pt_hip_sf: Point, pt_hip_sb: Point, pt_hip_cb: Point) -> HipDistribution` ¶

`calculate_waist_distribution(meas: BlouseMeasurements, pt_waist_cf: Point, pt_waist_sf: Point, pt_waist_sb: Point, pt_waist_cb: Point, side_seam_intake_max: float = 2.0 * CM) -> WaistDistribution` ¶

`sewpat.fitclass` ¶

`armscye_depth_ease: float` `property` ¶

`armscye_width_ease: float` `property` ¶

`back_width_ease: float` `property` ¶

`bust_point_ease: float` `property` ¶

`bust_width_ease: float` `property` ¶

`chest_width_ease: float` `property` ¶

`hip_ease: float` `property` ¶

`shoulder_width_ease: float` `property` ¶

`waist_ease: float` `property` ¶

`__post_init__() -> None` ¶

`range(field_name: str) -> _Range` ¶