---
myst:
    substitutions:
        macro:
            python: 1-5,15-21,24-36
            cpp: 4-5,11-14,17-27
        bloc1:
            python: 16-17
            cpp: 4,11
        bloc2:
            python: 30-31
            cpp: 22-23
---
# Macro "**modelerFlowrateLinearRegression.{{extension}}**"

## Objective

The objective of this macro is to build a linear regression between a predictor **rw** and a target 
variable **yhat** from the database contained in the ASCII file `flowrate_sampler_launcher_500.dat` 
defining values for the eight variables described in [](#launcher_introduction_simple_case_problem) 
on 500 patterns.

## Macro {{uranie}}

{{
    "```{literalinclude} " + parent_dir +
        "/roottest/uranie/doc/modeler/use_cases/" + language + "/modelerFlowrateLinearRegression." 
        + extension
    + "\n"
    + ":language: " + language + "\n"
    + ":lines: " + macro[language] + "\n"
    + "```"
}}

The {{tds}} is loaded with the database contained in the file `flowrate_sampler_launcher_500.dat` 
with the `fileDataRead` method:

{{
    "```{literalinclude} " + parent_dir +
        "/roottest/uranie/doc/modeler/use_cases/" + language + "/modelerFlowrateLinearRegression." 
        + extension 
    + "\n"
    + ":language: " + language + "\n"
    + ":lines: " + bloc1[language] + "\n"
    + "```"
}}

The linear regression is initialised and characteristic values are computed for **rw** with the 
`estimate` method:

{{
    "```{literalinclude} " + parent_dir +
        "/roottest/uranie/doc/modeler/use_cases/" + language + "/modelerFlowrateLinearRegression." 
        + extension 
    + "\n"
    + ":language: " + language + "\n"
    + ":lines: " + bloc2[language] + "\n"
    + "```"
}}

```{only} py
The last argument is the option field, which in most cases is empty. Here it is filled with 
"DummyPython" which helps specify to python which constructor to choose. There are indeed several 
possible constructors these 5 five first arguments, but C++ can make the difference between them as 
the literal members are either `std::string`, `ROOT::TString`, `Char_t*` or even `Option_t*`. For 
python, these format are all `PyString`, so the sixth argument is compulsory to disentangle the 
possibilities.
```

## Graph

{{
    "```{figure} " + parent_dir +
        "/roottest/build/uranie/doc/modeler/use_cases/" + language 
        + "/linear_regression/modelerFlowrateLinearRegression.png\n"
    + ":align: center\n"
    + ":name: use_cases_modelerFlowrateLinearRegression\n"
    + figure_scale + "\n"
    + "\n"
    + "Graph of the macro **\"modelerFlowrateLinearRegression." + extension + "\"**" + "\n"
    + "```"
}}