building.impact_catalogue

Impact insulation as a handbook prints it, one row per floor-ceiling.

The impact insulation class is a single number for a whole assembly. It is not a property of the slab, and it is not a property of the covering: it is what a tapping machine did on one floor built one way, with one ceiling under it, and it moves by fifty-five points between a bare concrete slab, which these pages rate 25, and the same slab under a wool carpet, which they rate 80. The models of phonometry.building.prediction compute the improvement a covering gives; this module holds what was measured on floors that exist, so a prediction has something published to sit beside.

Tables 32.1 to 32.7 print ImpactInsulation.impact_insulation_class, the IIC of a whole floor-ceiling assembly. Table 32.8 prints ImpactInsulation.impact_insulation_class_improvement, the delta-IIC a surface treatment adds to a hard massive floor. They are different quantities and no row of this catalogue carries both: one is a rating, the other is a difference between two ratings, and a caller who added the second to the first would be adding a difference to an absolute with nothing in the arithmetic to say so. Both are dimensionless.

The first edition of the handbook, in its Spanish translation of 1977, prints a third: ImpactInsulation.impact_sound_improvement_db, the average improvement in impact sound insulation a finish, a floating screed or a timber floor gives over a bare concrete slab, in decibels. It predates the IIC and is not one: it is a level difference averaged over frequency, and nothing on the page turns it into a rating or a rating into it. Tables 19.2 to 19.4 fill it and nothing else, and Table 19.4 adds the load each floor was measured under.

The IIC is a single-number rating and these pages print no frequency band at all: no impact sound pressure level per octave, none per third octave, and no reference curve. Neither do Tables 19.2 to 19.4 of the 1977 edition, whose chapter draws some of those improvements as curves against frequency in Figures 19.6 to 19.8; the figures are not transcribed. A caller after a band-by-band impact level will not find one in this catalogue, and nothing here can be turned into one.

The page numbers its constructions 1 to 38 straight through the seven tables, with a letter where a construction is printed as two lettered rows, and that printed number is the key of the row: "harris-1995-tables-32-1-to-32-8/34A" is the row the page calls 34A. It has to be, because about a dozen descriptions are printed in full and refer to another row rather than repeating the structural floor: “Igual que 1 salvo que…”, “Mismo suelo estructural que el 18”. The printed text is kept whole in name, the row it points at is in ImpactInsulation.refers_to_row, and resolving it is one lookup: PUBLISHED_IMPACT_INSULATION[f"{row.table}/{row.refers_to_row}"]. Table 32.8 numbers nothing, so its six rows are keyed by a slug of the printed treatment. A lettered pair is two rows and not one row in two conditions, which is why no row of Chapter 32 fills variant: 34A and 34B are each printed with a description and a rating of their own.

The 1977 tables number nothing either, and are keyed by a slug of the printed description in the same way. Table 19.4 prints one timber floor twice, unloaded and loaded, with nothing but the load to tell the two apart, so its rows carry the load in the key and in variant: that pair is one floor in two conditions, and Table 19.4 is the only table here whose rows fill it.

In building/data/harris-1995-tables-32-1-to-32-8.json and one file per table of Harris (1977), harris-1977-table-19-2.json to -19-4.json, read at import through the package-data reader in phonometry._internal, the same as every other catalogue here.

These tables print every dimension twice, in SI and in US customary units, and nineteen of the three hundred and twenty-one pairs are not each other: row 9 gives 16 in as 30,8 cm where the other eighteen 16 in of these tables are 40,6 cm, row 31 gives 2 in as 10,1 cm, row 38 gives 44 oz/yd2 as 1,99 kg/m2 where 28 and 30 give it as 1,5. They are registered as one entry in docs/ERRATA.md and nothing here quietly repairs them: the printed description is kept whole and the seventeen rows that carry one mark the cell in misprinted. One of the nineteen reaches a quantity rather than prose, which is why ImpactInsulation.layer_density_kg_m3 is empty on row 35A.

It is not a specification and it is not a prediction. The chapter says the tables hold “datos de mediciones” collected from a 1967 report prepared for the Federal Housing Administration by the National Bureau of Standards, and Table 32.8 credits a 1963 paper by Zeller; each row of Chapter 32 carries the one that covers its table in attributed_to, because a row read on its own would otherwise answer the same source for both. The 1977 tables credit no source and their rows carry none. No laboratory, no test standard and no uncertainty is named for any row. Table 32.8 carries a footnote of its own worth reading before its numbers are used anywhere: over wood-joist floors the improvement may be substantially smaller than the one printed.

Auto-generated from the source docstrings by scripts/generate_api_docs.py (make api-docs). Do not edit by hand.

impact_insulation_named(name: str) -> tuple[ImpactInsulation, ...]

Every published row whose printed description contains name.

Parameters

Returns: The matching rows, in catalogue order. Empty when none match. A tuple and not one row, because a description is not a name and several constructions share most of their words.

ImpactInsulation(
    *,
    name: str,
    source: str,
    table: str = '',
    variant: str = '',
    basis: Mapping[str, str] = ...,
    approximate: frozenset[str] = frozenset(),
    derived: Mapping[str, str] = ...,
    converted: Mapping[str, tuple[str, str]] = ...,
    carried: Mapping[str, str] = ...,
    ranges: Mapping[str, tuple[float | None, float | None]] = ...,
    bounded_above: frozenset[str] = frozenset(),
    bounded_below: frozenset[str] = frozenset(),
    reported: Mapping[str, tuple[float | tuple[float, float], ...]] = ...,
    unquantified: Mapping[str, str] = ...,
    uncertainty: Mapping[str, float] = ...,
    not_derivable: Mapping[str, str] = ...,
    misprinted: Mapping[str, str] = ...,
    attributed_to: Mapping[str, str] = ...,
    group: str = '',
    note: str = '',
    impact_insulation_class: float | None = None,
    impact_insulation_class_improvement: float | None = None,
    impact_sound_improvement_db: float | None = None,
    added_load_pa: float | None = None,
    refers_to_row: str = '',
    has_section_drawing: bool = False,
    layer_density_kg_m3: float | None = None,
)

One floor-ceiling construction or surface treatment, as printed.

The name, the citation and the hedges a cell can carry instead of a number are the ones every catalogue row has. What this class adds is that its three results are never filled together: a row is a rating (Tables 32.1 to 32.7), an improvement on a rating (Table 32.8) or an improvement in decibels (the 1977 Tables 19.2 to 19.4), and which one it is says which table it came from. The load a 1977 floor was measured under is a condition of the measurement, not a result, and sits beside the improvement it qualifies.

Attributes

ImpactInsulation.basis_of(field_name: str) -> str

What the source says this field is, one of CATALOGUE_BASES.

The five are measured, declared, calculated, estimated and extended.

Parameters

Returns: The field’s own entry in basis, else the row’s, else the empty string, which means the source does not say.

classmethod

ImpactInsulation.from_printed(**cells: Any) -> Self

A row built from the cells its page prints, completed and marked.

The one path that works anything out. The cells are what the page prints, under the field names of the class and with the hedges each cell carries, as a data file writes them. A figure written under a unit the class takes as an alias of its own (an AbsorptionAreaSpectrum takes absorption_area_125_ft2 for absorption_area_125_m2) is converted on its digits with an exact factor and rounded once, and converted records the figure and its unit. The row is then built and held to the contract the class docstring lists, so every cell is checked before any arithmetic reads it. Last, the class fills what follows from those cells (a modulus from a plate speed, a density and a Poisson ratio), never over a cell that holds a value or one the row says something else about, and derived says how each filled value was reached and, when the cells it rests on do not share one basis, the basis of each. Cells the arithmetic cannot take are refused rather than turned into a value that would be wrong: a modulus of 1 GPa and a shear modulus of 0.1 GPa give a Poisson ratio of 4, which no isotropic solid has, and a row whose cells are not meant to give a value says so in not_derivable, which keeps the arithmetic from running.

Cls(...) stays literal: it holds what it is given and works nothing out. To change a cell of a row and have what follows from it follow again, change it in printed_fields and build again here; dataclasses.replace would copy the derived values as they were:

cells = row.printed_fields()
cells["density_kg_m3"] = 2400.0
row = type(row).from_printed(**cells)

Parameters

Returns: The row, with what follows from its cells filled in.

Raises

ImpactInsulation.is_approximate(field_name: str) -> bool

Whether the page prints this field with a ~.

Parameters

Returns: True when the page rounded the cell on purpose.

ImpactInsulation.is_derived(field_name: str) -> bool

Whether this library computed this field instead of reading it.

Parameters

Returns: True when the page did not print it and the value follows from cells that it did. derived says how. A value the page prints in another unit, or gives by reference to another of its rows, answers False: the number is the page’s, and converted or carried says so.

ImpactInsulation.printed(
    field_name: str,
    *,
    wanted_by: str = 'the caller',
) -> float

One quantity this page prints, or a refusal that says what it had.

Every quantity of a row is optional, because the pages print different columns, so a caller passing one into a function that requires a float has to narrow it. Doing it here beats an assertion at each call site: the refusal names the field, who wanted it and what the page had in that cell, which is the difference between a cell the book left empty and a cell holding the word “model”.

Parameters

Returns: The value, as a float.

Raises

ImpactInsulation.printed_fields() -> dict[str, Any]

The cells the page prints, as from_printed takes them.

Every field, the name, the citation, the table and every hedge included, except the values this library derived, derived itself, and a field left at a default that holds nothing (a quantity the page leaves out, an empty text or hedge). A text field whose default says something is kept even when it holds no text: the per of an area per unit is a person unless the row says otherwise, and a row that leaves it empty has said otherwise. A value converted from the page’s unit and one the page gives by reference to another of its rows are the page’s, so they stay, with converted and carried beside them.

For every row from_printed builds, and so for every packaged one, type(row).from_printed(**row.printed_fields()) is the row again, and changing a cell before building it again is how a row is edited without carrying a derived value that no longer follows from it. A derived passed to the literal constructor is the caller’s own; it is left out here with its value, like every derived one, so building again gives back only what the class works out.

Returns: A new dictionary of constructor keywords. The values are the ones the row holds, frozen as the row holds them.

ImpactInsulation.why_missing(field_name: str) -> str

Why this field is None, in the page’s own terms.

A catalogue that answers None and stops is asking the caller to guess whether the material has no such property, whether the book measured it and printed a dash, or whether the cell holds something that is not a number. Each of those is a different answer.

Parameters

Returns: What the page had in that cell, or the empty string when the field is not missing at all. A field the page has no column for and this library cannot derive, because the cells it would need are themselves a range, answers that it does not follow.

Raises

Constant (mapping).