Minuit++ URD

Nick van Eijndhoven (Nick@fys.ruu.nl)
Mon, 20 Oct 1997 16:32:39 +0200 (MET DST)

Dear Jamie,
Unfortunately I can't be present at the Minuit++ URD discussion 23-oct-1997.
However, I had a look at the document of Zbyszek in trying to figure
quickly out how I (in doing my physics analysis) could easily try out
several different fits through my data points or distribution.
I was not able (being a simple physicist) to get that from the URD.ps file;
it looks too much as some writeup promising lots of things in future
too me without telling what real functionality one can expect from it
in doing the real (=physics analysis) work.
So as input to the discussion I just can tell you here what functionality
I would like to have.
First of all : please make the documents available via some central
WWW homepage, since from outside CERN going to some /afs directory
to ftp the .ps file is a pain in the ass.

1) Having some data points or some distribution I would like to view
the data in a plot first.

2) Now I would like to 'click' at the plot and obtain a menu from which
I could select e.g. FIT.

3) Then a second menu should pop up in which I can select the boundaries
of the fit and the fitting function (either some standard ones like
Polynomial, Gaussian etc... or "user function")

4) Having selected a certain function I should be able to provide
additional info (e.g. order of polynomial) or just provide the C++
code for a user function.

5) Clicking eventually on the "OK" button should perform the fit and
show me the fit curve + parameter values in the same plot as
my data points.

6) Clearly I would like to repeat steps 2)-5) to try out several functions,
boundaries etc....

Bottom line : I want to get completely rid of this hastle of providing
a FCN function as it was in the old FORTRAN case.

However, the possibility of 'doing it the old way' (but then in C++)
should still be there.

The above is based on my experience in performing my complete WA93 direct
photon analysis in C++ (using the ROOT framework) and it turned out that
having these tools available has saved me a lot of time !

Cheers,
Nick.

*----------------------------------------------------------------------*
Dr. Nick van Eijndhoven Department of Subatomic Physics
email : nick@fys.ruu.nl Utrecht University / NIKHEF
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fax. +31-30-2518689 The Netherlands
WWW : http://www.fys.ruu.nl/~nick Office : Ornstein lab. 172
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