Studies

In the context of this program, a study is based on a dataset containing dates.
From these data, a set of computations are done, leading to the statistical tests:
init
splitBuild the sub-groups
observedCompute the distributions for each split
controlBuild the control groups
expectedBuild the expected distributions from control groups
chi2Compute chi-square test
outputGenerate a presentation of the results
(orange : computations specific to each study - green : computations common to all studies)
These computations are done issuing commands with the CLI run-observe.php (CLI = Command Line Inerface, a tool used in a console).
The intermediate data generated by the commands are stored in the working directory of the study.
Except for command output, which generates its results in the output directory.

Splits

We often need to divide the original dataset in different subgroups to see if they show different distributions.
For example, how do the distributions of babies who died a few days after their birth compare with the distributions of general population ?
In this program, this is handled by the notion of split.
A split permits to generate subgroups from the original groups.
In general, a study has a split with only one subgroup containing the whole dataset.

The working directory

Taking the example of a dataset with birth and death dates, and a study which defines one split, called "age" (making sub-groups depending on the age at death):
working-dir
├── controls
│   ├── control-001
│   │   ├── birth
│   │   ├── birth-death
│   │   └── death
│   ├── ...
│   └── control-100
│       ├── birth
│       ├── birth-death
│       └── death
├── split-age
│   ├── 01--0-2days
│   │   ├── chi2
│   │   ├── data.bz2
│   │   ├── expected
│   │   │    ├── birth
│   │   │    ├── birth-death
│   │   │    └── death
│   │   └── observed
│   │        ├── birth
│   │        ├── birth-death
│   │        └── death
│   ├── ...
│   └── 08--90years-150years
│       ├── chi2
│       ├── data.bz2
│       ├── expected
│       │    ├── birth
│       │    ├── birth-death
│       │    └── death
│       └── observed
│            ├── birth
│            ├── birth-death
│            └── death
└── split-all
    └── 01--0-150years
        ├── chi2
        ├── data.bz2
        ├── expected
        │    ├── birth
        │    ├── birth-death
        │    └── death
        └── observed
             ├── birth
             ├── birth-death
             └── death

Study file