Calling a math function with correct function parameters

There is a math library called alglib
(see here:  https://www.mql5.com/en/code/11077)
and I want to call the LSFitLinearC function
but I am not really sure how to call it
with parameters that compile correctly.

Here is an example of someone using:
https://www.mql5.com/en/articles/2646

I am not sure why in this example they
are using objects like CMatrixDouble,
when the function decleration looks like this:

static void CAlglib::LSFitLinearC(double &y[],CMatrixDouble &fmatrix,
                                  CMatrixDouble &cmatrix,int &info,
                                  double &c[],CLSFitReportShell &rep)


So I want a sample script calling this function
with a few data points (time and price) from
the EUR/USD chart and get a valid output.
You should get back a value in "c" parameter.

This should be a simple task just to create
a sample script to correctly call this function.

Although this not necessary to know, here is more
information about this function:   This is a linear
regression calculation similar to the one used
in regression channels.  You can find an example
call in the alglib library documentation here:
http://www.alglib.net/translator/man/manual.ipython.html#example_lsfit_d_linc