The Data Space

Input data shared by every by-policy projection.

The four input CSVs are read here, once per model, and referenced from Projection as data. Projection is parameterized by point_id, so each Projection[N] is a separate ItemSpace with its own cells cache; if the readers lived there, every model point would re-read every file. Holding them in an unparameterized Space reads each file once no matter how many policies are projected.

Inputs are external files: plain CSVs in the model folder’s parent directory, products/term_assurance/, rather than data stored inside the model. The model folder therefore holds nothing but formulas — no _data/, no IOSpec, no embedded values — so a diff of the model shows logic changes only. This follows annuallife.TradLife_A; contrast basiclife.BasicTerm_S, which keeps its inputs inside the model through modelx’s IOSpec machinery.

The consequence worth knowing: the model is not portable on its own. Copying the Term_UK_S folder without its parent’s CSVs produces a model that reads and then fails on first evaluation.

input_dir() resolves the directory from _model.path.parent at run time, so the model works wherever the repository is checked out. Each table has a filename Reference and a reader Cells:

Reference	Cells	File
model_point_file	model_point_table()	model_point_table.csv
mort_table_file	mort_table()	mort_table.csv
select_factor_file	select_factor_table()	select_factor_table.csv
lapse_table_file	lapse_table()	lapse_table.csv

To swap in a licensed mortality basis — the CMI “16” Series assured lives tables TMNL16/TFNL16, which are subscriber-restricted and cannot be redistributed here — replace mort_table.csv and select_factor_table.csv with same-schema files, or point mort_table_file and select_factor_file at different names, then clear the cache. No formula changes: the mortality lookup already carries the select-duration argument the UK tables need.

Cells Descriptions

input_dir()

The directory holding the input CSVs: the model folder’s parent.

Inputs are external files, not data stored inside the model, so the model folder is pure formulas. The path is resolved at run time from where the model was read, following annuallife.TradLife_A.

model_point_table()

The model point table, read from model_point_table.csv.

mort_table()

The mortality rates by sex, smoker status and age, from mort_table.csv.

Read as the applied best-estimate rate on the applied mortality basis and as the ultimate rate on the select basis; see Projection.mort_basis.

select_factor_table()

The select-duration factors, read from select_factor_table.csv.

lapse_table()

The lapse rates by policy year, read from lapse_table.csv.

The policy_year key is the contractual 1-based label (1, 2, …, 6+), not the projection’s 0-based month index t; Projection.lapse_rate_base reads the row policy_year(t) = t // 12 + 1, and the rate it returns is the annual one the table is quoted in.