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  28   20 Jul 2004 Konstantin Olchanski Introduction of environment variable MIDASSYS
> > Starting from midas version 1.9.4 on, the environment variable 'MIDASSYS' ...
> 2. What will the entire structure tree look like?
> 
> Here's my suggestion
> MIDASSYS=/opt/midas-1.9.4 (for example)   

Where should MIDAS be installed?

After looking at the LSB and at the FHS, it appears that the standards permit all of:
1) /opt/midas...
2) /usr/{bin,lib,...}
3) /usr/local/{bin,lib,...}

Some handy references:
http://www.pathname.com/fhs/pub/fhs-2.3.html
http://www.linuxbase.org/spec/

The "example LSB-compliant packages" appear to install into /opt/lsb, but I do not see
 any guidance as to where "my" packages should go.

Then, after some googling, I see that IBM "recommends" /opt (see
http://www-106.ibm.com/developerworks/linux/library/l-lsb.html):

begin-quote---
To avoid name space collisions when installing LSB-conforming applications, the
applications belonging to the base operating system or the distribution are to be
installed in /sbin/, /bin/, or /usr/. System administrators can build packages from
source and install them into the /usr/local/ directory. However, third-party packages
of add-on software must be installed in /opt/<package>/, where <package> is the name
that describes a software suite.
end-quote---


K.O.
  27   15 Jul 2004 Konstantin Olchanski future direction discussion?
> > Are we ready for 2.0? 

I disapprove of version number inflation. Why not go straight for midas version
3000-Pro-Z?

> A big thing along the horizon I see is the ROME environment
> (http://midas.psi.ch/rome/). So we will move away from PAW to ROOT. Although
> the DAQ part will stay untouched, the whole analysis back-end changes,
> including some XML configuration and MySQL support.

I looked at the ROME slides from Pierre, and it seems to suffer badly from the
second-system syndrome (read The Mythical Man-Month).

For us, it is important to get the data into a form where we can process it with
ROOT and I would prefer if we could concentrate in improving the (embryonic) ROOT
online analysis capabilities.

> > 1) For one I would like to explore memory mapping (mmap())

It is trivial to replace System-V shared memory with mmap(). I am surprised that
it has not been done yet. System-V semaphores are a little bit harder to get rid of.

> > 2) Expanding hardware support: 
> >    a) custom microcontrolers?
> >    b) more hardware
> >    c) how about a "standard" Linux device /dev/midas
> >    for various PCI cards (PCI<->CAMAC) (PCI<->VME) 

We cannot expect MIDAS Authors to provide drivers for all possible hardware.

At best, we can mount an effort to collect exisiting drivers from all MIDAS users
"out there" and to integrate them into MIDAS.

Even that is highly non-trivial- many drivers use non-portable native hardware
access interfaces (direct bit-banging on PPCs, VMIC library on VMIC Linux
machines, etc). We have already failed to create an efficient generic portable VME
access library.

> As for a), there is the MSCB system (http://midas.psi.ch/mscb)

I never saw the point of having tons of MIDAS code for MSCB hardware that nobody
has and nobody will ever have.

> > 3) I have never really seen a midas deployment that uses interrupts. 
>
> It's not only the "ease" of polling, but also that it's faster (in almost all
> cases) and less troublesome. But hey, interrupt support is included in mfe.c,
> so if you are fanatic about interrupts...

Interrupts are important when one cannot afford chewing up CPU cycles, memory
cycles, PCI cycles and VME cycles on polling.

As I understand, common CAMAC hardware does not generate interrupts- this explains
lack of examples and lack of interrupt use. At TRIUMF, our new VME hardware
supports interrupts and I have a VMIC-based setup where I can (and intend to) test
MIDAS support of interrupts.

K.O.
  26   15 Jul 2004 Stefan Ritt Severe bug in 1.9.4
Hello midas'ers,

Today I discovered a severe bug in the routine bm_check_buffers(), which
causes the logger to crash when it stops a run due to a reached event limit.
The funny thing is that this bug was there since the beginning, but only
recent versions of gcc and libc reveal it.

Since I consider this severe, I fixed it and updated 1.9.4 just now. I did
not go with 1.9.4-1, but maybe in future we should consider patch levels.

So please everybody who uses 1.9.4 and has problems with crashing loggers,
please update to 1.9.4 from today (July 15th, 2004).

- Stefan
  25   14 Jul 2004 Stefan Ritt future direction discussion?
Have changed your entry as Non-HTML (easier to reply to...)

Here are some "initial" comments, by no means complete...

> Are we ready for 2.0? 
> Stefan - do you have any ideas/enhancements?

A big thing along the horizon I see is the ROME environment
(http://midas.psi.ch/rome/). So we will move away from PAW to ROOT. Although
the DAQ part will stay untouched, the whole analysis back-end changes,
including some XML configuration and MySQL support. I guess that would justify
a 2.0. I will discuss this at TRIUMF when I come in September, see how useful
ROME is for other users...

> 1) For one I would like to explore memory mapping (mmap()) on Linux
> - I've used it once upon a time on DEC OSF/1 and I found it really
> nice compared to shared memory. 
> From a user standpoint it behaves as a shared memory but is mapped 
> to a real file that can be easily "removed" when neccessary. 
> One really annoying thing in MIDAS is when it goes ballistic
> the cleanup which is somewhat tricky. 
> The question if there is any performance penalty associated

I guess there are no performance penalties, since under the hood both
techniques are handled similarly. The problem is that besides share memories
you need also semaphores to controll exclusive access to the memory, either
shm() funcitons or mmap(), so this would only fix half of the problem. I seem
to remember that mmap() was not available on some Ultix systems or so, but I
guess that's obsolete by now...

> 2) Expanding hardware support: 
>    a) custom microcontrolers?
>    b) more hardware
>    c) how about a "standard" Linux device /dev/midas
>    for various PCI cards (PCI<->CAMAC) (PCI<->VME) 

Well, you cannot develop hardware support for hardware you don't have, so the
policy up to now was that everyone developing some special drivers or hardware
support contributed it to the package. About c), we have already a CAMAC
driver standard, but at the user space level, so I don't see the benefit of
having kernel-mode standardized drivers. The only difference will be that the
debugging will be harder. VME standard is there in a kind of poor start right
now, but I expect to finish it this fall.

As for a), there is the MSCB system (http://midas.psi.ch/mscb) which has midas
support on the device driver and bus driver level, but I learned that
distributing hardware (or PCB designs if you like) is much harder than sharing
software. 

> 3) I have never really seen a midas deployment that uses interrupts. 
> I do understand the ease of polling and the fact that these days
> CPU's are cheap but sometimes it is important to use interrupts.
> Any examples/experience?

It's not only the "ease" of polling, but also that it's faster (in almost all
cases) and less troublesome. But hey, interrupt support is included in mfe.c,
so if you are fanatic about interrupts, please feel free to use them.
  24   14 Jul 2004 Piotr Zolnierczuk future directions discussion?
Sorry the previous message got mangled:

Hi, 
I think that rather than spending too much time on where to put files 
and how to define the environment - I am guilty of that myself -  we should 
perhaps have some discussion on the future of MIDAS. 

Are we ready for 2.0? 

Stefan - do you have any ideas/enhancements? 

1) For one I would like to explore memory mapping (mmap()) on Linux.
I've used it once upon a time on DEC OSF/1 and I found it really nice 
compared to shared memory. From a user standpoint it behaves as a shared
memory but is mapped to a real file that can be easily "removed" when 
neccessary. One really annoying thing in MIDAS is when it goes ballistic 
the cleanup is somewhat tricky. 
The question if there is any performance penalty associated 

2) Expanding hardware support: 
  a) custom microcontrolers? 
  b) other hardware
  c) how about a "standard" Linux device /dev/midas for various 
  PCI cards (PCI<->CAMAC) (PCI<->VME) 

3) I have never really seen a midas deployment that uses interrupts. 
I do understand the ease of polling and the fact that these days CPU's 
are cheap but sometimes it is important to use interrupts. 

Any examples/experience? 

?) 

Piotr
  23   14 Jul 2004 Piotr Zolnierczuk future direction discussion?
Hi,
  I think that rather than spending too much time on where to 
put files and how to define the environment - I am guilty of that myself.
We should be perhaps have some discussion on the future of MIDAS.

Are we ready for 2.0? 
Stefan - do you have any ideas/enhancements?

1) For one I would like to explore memory mapping (mmap()) on Linux
- I've used it once upon a time on DEC OSF/1 and I found it really
nice compared to shared memory. 
From a user standpoint it behaves as a shared memory but is mapped 
to a real file that can be easily "removed" when neccessary. 
One really annoying thing in MIDAS is when it goes ballistic
the cleanup which is somewhat tricky. 
The question if there is any performance penalty associated

2) Expanding hardware support: 
   a) custom microcontrolers?
   b) more hardware
   c) how about a "standard" Linux device /dev/midas
   for various PCI cards (PCI<->CAMAC) (PCI<->VME) 

3) I have never really seen a midas deployment that uses interrupts. 
I do understand the ease of polling and the fact that these days
CPU's are cheap but sometimes it is important to use interrupts.
Any examples/experience?

?)

Piotr
  22   12 Jul 2004 Stefan Ritt Introduction of environment variable MIDASSYS
> With POSIX there is a written standard, which says that each pacakge goes in
> it's own
> directory under /opt. eg. /opt/midas.  Each package gets to define it's own
> structure
> within that directory.  One could imagine several versions installed at the
> same time
> /opt/midas/v1.9.2 and /opt/midas/v1.9.4 each with a bin, lib include etc. 
> Following the
> ROOT example, you could make a link from /opt/midas/pro to
> /opt/midas/v1.9.4, so that
> system files and login files are easy to maintain etc.  The basic idea is
> 
> MIDASSYS=/opt/midas/pro
> PATH=$PATH:$MIDASSYS/bin
> 
> though a more sophisticated approach is
> 
> MIDASSYS=/opt/midas/pro
> echo $PATH | grep -q $MIDASSYS || PATH=$PATH:$MIDASSYS/bin
> 
> where the assignment line (Bourne shell, and BASH shell) ensures
> that multiple entries are not added on the PATH even if the script is more
> than once.

That sounds all very good to me. So can you please sit together (at least John,
Piotr, and Pierre-Andre), discuss a common scheme and and propose it officially in
this forum for comments. After a week or so, it should be implemented into the
Makefile and installation scripts. I also would like to have Paul Knowles giving
it a look, since he voluteered to make the midas RPMs, which also heavily depends
on the chosen directory structure.
  21   09 Jul 2004 John M O'Donnell Introduction of environment variable MIDASSYS
For a long time the "de facto" standard was to spread a package around in many
directories under /usr/local.  This proved to be a bad idea, as removing the
package
became very difficult.

With POSIX there is a written standard, which says that each pacakge goes in
it's own
directory under /opt. eg. /opt/midas.  Each package gets to define it's own
structure
within that directory.  One could imagine several versions installed at the
same time
/opt/midas/v1.9.2 and /opt/midas/v1.9.4 each with a bin, lib include etc. 
Following the
ROOT example, you could make a link from /opt/midas/pro to
/opt/midas/v1.9.4, so that
system files and login files are easy to maintain etc.  The basic idea is

MIDASSYS=/opt/midas/pro
PATH=$PATH:$MIDASSYS/bin

though a more sophisticated approach is

MIDASSYS=/opt/midas/pro
echo $PATH | grep -q $MIDASSYS || PATH=$PATH:$MIDASSYS/bin

where the assignment line (Bourne shell, and BASH shell) ensures
that multiple entries are not added on the PATH even if the script is more
than once.

POSIX also goes on to say that links from /opt/bin can be made if desired. 
I find this
usefull if a package has only one or two executables, and I don't to make
multiple
versions available.

I hope that the POSIX ideas are usefull,

John.

> > Here's my suggestion
> > MIDASSYS=/opt/midas-1.9.4 (for example)   
> 
> I guess we should follow the "standard" as much as possible. MIDASSYS was
inspired by
> ROOTSYS. Now where do people usually install ROOT? Is it /opt/root-x.x.x
or something
> else. Some years ago (when I did the last time some linux administration)
optional
> packages were put into /usr/local by default. I guess you have more
experience with
> today's tradition, so do whatever you thing is standard.
> 
> > so the Linux binaries would go to 
> > MIDASHOST=i386-pc-linux-gnu
> > $MIDASSYS/$MIDASHOST/bin
> > $MIDASSYS/$MIDASHOST/lib
> 
> Does that mean that the path has to be modified to include
$MIDASSYS/$MIDASHOST/bin?
> If we put a link to /usr/local/bin, the path does not have to be modified.
What about
> shared libraries? Does ldconfig know about /usr/local/lib, or
$MIDASYS/$MIDASHOST/lib?
> 
> > and the shared stuff would go to 
> > $MIDASSYS/include
> > $MIDASSYS/share/drivers
> > $MIDASSYS/share/examples
> 
> What about /usr/share? Is that a common place for documentatino etc?
> 
> Thanks for your advice.
> 
> - Stefan
  20   09 Jul 2004 Piotr Zolnierczuk Introduction of environment variable MIDASSYS
> I guess we should follow the "standard" as much as possible. MIDASSYS was inspired by
> ROOTSYS. Now where do people usually install ROOT? Is it /opt/root-x.x.x or something
> else. Some years ago (when I did the last time some linux administration) optional
> packages were put into /usr/local by default. I guess you have more experience with
> today's tradition, so do whatever you thing is standard.
I agree that we should follow the standard. 
I used /opt as an example. 
There are several "schools" as to where put things my philosophy is
/usr/{bin,lib,include}       - std OS packages (RPMS, .deb or whatever your flavor likes)
/usr/local/{bin,lib,include} - make/make install packages
/opt/..                      - additional packages (RPMS, ...) 

But it should be up to the user what $MIDASSYS she/he likes.

> 
> > so the Linux binaries would go to 
> > MIDASHOST=i386-pc-linux-gnu
> > $MIDASSYS/$MIDASHOST/bin
> > $MIDASSYS/$MIDASHOST/lib
> 
> Does that mean that the path has to be modified to include $MIDASSYS/$MIDASHOST/bin?
> If we put a link to /usr/local/bin, the path does not have to be modified. What about
> shared libraries? Does ldconfig know about /usr/local/lib, or $MIDASYS/$MIDASHOST/lib?
The path could/should be modified in users .bashrc/.tcshrc or we could provide a simple
system-wide script(s) that would do the job.
For years, I've been using such a scenario on my Linux PCs with regards to various
add-on packages (e.g. cern). 

Here's an example of my cern.sh that goes into /etc/profile.d on my RedHat Linux PC
#===================================
. /etc/profile.d/.functions
export CERN=/cern
export CERN_LEVEL=pro
addpath $CERN/$CERN_LEVEL/bin
#===================================

As for library path: there are several ways (as with exec path)
a) nice way: modify /etc/ld.so.conf by adding $MIDASYS/$MIDASHOST/lib
b) modifying LD_LIBRARY_PATH (there's some security issues with it)
c) symlinking to /usr/local/lib


> 
> What about /usr/share? Is that a common place for documentatino etc?
Yes. Check any recent Linux distribution /usr/share is full of docs, icons, etc.

This is my bias. 

I (obviously) prefer packing things into rpm which makes install/updates 
very easy - especially if you are managing several machines.

Cheers
    Piotr
  19   09 Jul 2004 Stefan Ritt Introduction of environment variable MIDASSYS
> Here's my suggestion
> MIDASSYS=/opt/midas-1.9.4 (for example)   

I guess we should follow the "standard" as much as possible. MIDASSYS was inspired by
ROOTSYS. Now where do people usually install ROOT? Is it /opt/root-x.x.x or something
else. Some years ago (when I did the last time some linux administration) optional
packages were put into /usr/local by default. I guess you have more experience with
today's tradition, so do whatever you thing is standard.

> so the Linux binaries would go to 
> MIDASHOST=i386-pc-linux-gnu
> $MIDASSYS/$MIDASHOST/bin
> $MIDASSYS/$MIDASHOST/lib

Does that mean that the path has to be modified to include $MIDASSYS/$MIDASHOST/bin?
If we put a link to /usr/local/bin, the path does not have to be modified. What about
shared libraries? Does ldconfig know about /usr/local/lib, or $MIDASYS/$MIDASHOST/lib?

> and the shared stuff would go to 
> $MIDASSYS/include
> $MIDASSYS/share/drivers
> $MIDASSYS/share/examples

What about /usr/share? Is that a common place for documentatino etc?

Thanks for your advice.

- Stefan
  18   09 Jul 2004 Piotr Zolnierczuk Introduction of environment variable MIDASSYS
> Starting from midas version 1.9.4 on, the environment variable 'MIDASSYS'
> should be defined and point to the installation directory of midas. The
> purpose of that is that add-on packages (like the upcoming ROME system) can
> find the midas libraries and include files. It is excatly the same as for
> ROOT which defines ROOTSYS and should therefore be straight forward. The
> libraries should then reside in $MIDASSYS/lib (or %MIDASSYS%\lib under windows).
> 
> To remind users about this new variable, a test has been added to odbedit,
> which shows a warning when starting odbedit and MIDASSYS is not defined.

1. Finally! It's about time to do that! 

2. What will the entire structure tree look like?

Here's my suggestion
MIDASSYS=/opt/midas-1.9.4 (for example)   


so the Linux binaries would go to 
MIDASHOST=i386-pc-linux-gnu
$MIDASSYS/$MIDASHOST/bin
$MIDASSYS/$MIDASHOST/lib

the VxWorks binaries
MIDASHOST=m68k-wrs-vxworks
$MIDASSYS/$MIDASHOST/bin
$MIDASSYS/$MIDASHOST/lib

and the shared stuff would go to 
$MIDASSYS/include
$MIDASSYS/share/drivers
$MIDASSYS/share/examples

The Makefile would need to be adjusted (for make install) but that is not
too complicated

What do you think?

Regards
  Piotr
  17   09 Jul 2004 Stefan Ritt Version 1.9.4 released today
Version 1.9.4 of midas has been released today. It is mainly a maintenance
update, for all the little things which have been fixed since the last
release, and does not contain major new functionality.
  16   09 Jul 2004 Stefan Ritt Introduction of environment variable MIDASSYS
Starting from midas version 1.9.4 on, the environment variable 'MIDASSYS'
should be defined and point to the installation directory of midas. The
purpose of that is that add-on packages (like the upcoming ROME system) can
find the midas libraries and include files. It is excatly the same as for
ROOT which defines ROOTSYS and should therefore be straight forward. The
libraries should then reside in $MIDASSYS/lib (or %MIDASSYS%\lib under windows).

To remind users about this new variable, a test has been added to odbedit,
which shows a warning when starting odbedit and MIDASSYS is not defined.
  15   29 Jun 2004 Konstantin Olchanski FAQ: anonymous cvs access?
> Is the midas CVS server set-up so that I can pull the newest 
> version off the CVS server?
> 
> What would be my CVSROOT?
> pserver:anoncvs@midas.psi.ch:/cvs/midas *this did not work* :)

I use:

setenv CVS_RSH ssh
cvs -d cvs@midas.psi.ch:/usr/local/cvsroot checkout midas

It works most of the time. Sometimes I get locking and "permission denied"
errors on some subdirectories, presumably when CVS is being reorganized or
when there are stale locks. Does not happen too often.

K.O.
  14   22 Jun 2004 Exaos Lee FAQ: anonymous cvs access?
> In the Midas doc under "Quick Start"
> http://midas.triumf.ca/doc/html/quickstart.html
> you will find the proper cvs command for accessing the latest cvs Midas
> version. The public pwd is cvs. You will only be able to checkout/update the
> package.

I cannot checkout module:
------------
01:52:16: pc2075.psi.ch: Operation timed out
01:52:16: cvs [checkout aborted]: end of file from server (consult above
messages if any)
------------

Could anybody add download tar package in the WWW interface of CVS repository.
I know the original CGI script has such a feature. Thanks.
  13   21 Jun 2004 Pierre-André Amaudruz FAQ: anonymous cvs access?
> Is the midas CVS server set-up so that I can pull the newest 
> version off the CVS server?
> 
> What would be my CVSROOT?
> pserver:anoncvs@midas.psi.ch:/cvs/midas *this did not work* :)
> 
> Piotr
> 
>  

In the Midas doc under "Quick Start"
http://midas.triumf.ca/doc/html/quickstart.html
you will find the proper cvs command for accessing the latest cvs Midas
version. The public pwd is cvs. You will only be able to checkout/update the
package.
  12   21 Jun 2004 Piotr Zolnierczuk FAQ: anonymous cvs access?
Is the midas CVS server set-up so that I can pull the newest 
version off the CVS server?

What would be my CVSROOT?
pserver:anoncvs@midas.psi.ch:/cvs/midas *this did not work* :)

Piotr

 
  11   11 Mar 2004 Renee Poutissou Creation of secondary Midas output file.
Jan , 

Do you need to log this stage 1 output?  If not, you would use the 
eventbuilder mechanism to create your stage 2 events.  
I use the eventbuilder mechanism with success for my TWIST experiment.

Renee
  10   10 Mar 2004 Stefan Ritt Creation of secondary Midas output file.
Dear Jan,

I had a look at your code. You create a gPhysicsEventHeader array, fill it, and expect the 
framework to write it to disk. But how can the framework "guess" that you want your private 
global array being written? Unfortunately it cannot do magic!

Do do what you want, you have to write a "secondary" midas file yourself. I modified your 
code to do that. First, I define the event storage like

BYTE           gSecEvent[ MAX_EVENT_SIZE ];
EVENT_HEADER   *gPhysicsEventHeader = (EVENT_HEADER *) gSecEvent;
WORD* 	       gPhysicsEventData = ( WORD * )( gPhysicsEventHeader + 1 );		

I use gSecEvent as a BYTE array, since it only contains one avent at a time, so this is more 
appropriate. Then, in the BOR routine, I open a file:

  sprintf(str, "sec%05d.mid", run_number);
  sec_fh = open(str, O_CREAT | O_RDWR | O_BINARY, 0644);

and close it in the EOR routine

  close(sec_fh);

The event routine now manually fills events into the secondary file:

      /* write event to secondary .mid file */
      gPhysicsEventHeader->data_size = bk_size(gPhysicsEventData);
      write(sec_fh, gPhysicsEventHeader, sizeof(EVENT_HEADER)+bk_size(gPhysicsEventData));

Note that this code is placed *inside* the for() loop over nItems, so for each detector you 
create and event and write it.

That's all you need, the full file adccalib.c is attached. I tried to produce a sec01220.mid 
file and was able to read it back with the mdump utility.

Best regards,

  Stefan
  9   10 Mar 2004 Jan Wouters Creation of secondary Midas output file.
Dear Midas Team,

I have run into a problem with Midas and was wondering if you could explain what I 
am doing wrong.  I have included a simple demo to illustrate what I am doing and 
can send a small input data file if needed.

WHAT I AM TRYING TO DO:
Every midas event for the DANCE experiment consists of many physics events.  I am 
trying to create a secondary mid file where the event boundaries are now the 
physics events rather than the midas events.  This secondary mid file will be 
analyzed using a second stage midas analyzer.

For the demo, I use the data from EV02 (one of our 15 frontends), which consists of a 
variable number of fixed length structures where each structure contains the data for 
one crystal from the DANCE detector. 
 I treat each crystal as a separate physics event and write it out in the TREK bank, 
which is a demo calculated output bank, as a separate event.   

(The only difference between this demo and our real system is that we would include 
all the crystals from the other frontends that have approximately the same time stamp 
in the output bank.  Thus the output bank would consist of a varing number of 
crystals in one event rather than the fixed one crystal per event used in this demo.)

THE CHANGES TO analyzer.c AND adccalib.c
I loop through the EV02 bank examining each crystal structure in turn.  I calculate 
"calibrated" parameters and put them into an output bank called TREK.  The unusual 
part of this example is that the TREK bank is no longer part of the main list of input 
banks, ana_trigger_bank_list[].   Instead it is now part of a new bank list called 
ana_physics_bank_list[].  See the analyzer.c file for this definition.

In adccalib.c I  create the space for this new bank as follows. 

	EVENT_HEADER 	gPhysicsEventHeaders[ MAX_EVENT_SIZE / sizeof( 
EVENT_HEADER ) ];  
	WORD* 		gPhysicsEventData = ( WORD * )( gPhysicsEventHeaders + 1 );		

In the adc_calib routine I create the bank header as follows.  Note that the serial 
numbers will restart at 0 at the beginning of each midas event.  Should I let the serial 
number increment monotonically until the end of the run?:

	gPhysicsEventHeaders->serial_number = (DWORD) - 1;
	gPhysicsEventHeaders->event_id = 2;
	gPhysicsEventHeaders->trigger_mask = 0;
	gPhysicsEventHeaders->time_stamp = pheader->time_stamp;

In a loop that loops through all the crystals contained in EV02,  I extract each crystal, 
calibrate it, and store it in a TREK structure.  In creating the TREK bank I assume that 
each one will be a separate physics event thus I update the event serial number and 
use bk_init32 to initialize the memory.   

   	for ( short i = 0; i < nItems; i++ )
  	{	++(gPhysicsEventHeaders->serial_number);  	// Update serial number.
  		bk_init32( gPhysicsEventData );		// Initialize storage.
  		bk_create( gPhysicsEventData, "TREK", TID_STRUCT, &trek );
  	
  		trek->one = (double) pev->areahg * 1.0;
  		trek->two = (float) pev->timelo * 1.0;

  		bk_close( gPhysicsEventData, trek+1 );
  		
  		pev++; 					// Loop to next crystal's data. 
	}	

The output bank should consist of multiple events for each individual EV02 midas 
input event. 

 As far as I can tell the code compiles and runs fine, but I get no data in the .mid 
output file except for the ODB. I have a print statement at the beginning of each 
midas event stating how many crystals were found in the EV02 bank.  I also print out 
the calibrated value for each crystal as it is being placed in its own TREK output 
bank.  The data appears correct.

 I cannot place TREK in the input bank the way it normally is done in the examples 
because there is not a one-to-one correspondence between a midas event and a 
true physics event.  Instead one midas event has many physics events.  Thus the 
output bank needs to be in a new memory area so that I can create a custom header 
and increment the serial number properly for each event.  Our follow-on analysis 
using a second Midas analyzer only needs to analyze one physics event at a time 
rather than one Midas event at a time, which is why we are going to all the trouble to 
get this paradigm working.

I include all the code for this very simple example. 

RUNNING THE CODE:
To run the example just use the run01220.mid file I will send:

./analyzer -i run01220.mid.gz -o run01220out.mid -c settings.odb_cfg -n 50

The only thing done by the settings.odb_cfg file is to turn on the TREK output bank.  I 
have verified that the bank is on.

SUMMARY:
I believe that I must not be creating the new TREK output bank correctly so that 
midas understands that the event-by-event calculated physics data should be written 
out event-by-event.  I have pointed out several places in the above discussion where 
I might be making a mistake.

I would like to get both this example running and a similar which create Root trees, 
though the Root trees are of secondary importance.  With this example I can finish 
writing the second stage analyzer and get the DANCE collaboration moving forward 
with their analysis.  Currently, we cannot use this paradigm because I cannot create 
a secondary mid file in our stage one analysis.  I would be very grateful if you could 
take a look at this example and tell me what I am doing incorrectly.

Jan
ELOG V3.1.4-2e1708b5