++ed by:
AMBA

1 PAUSE user
1 non-PAUSE user.

Andreas K. Hüttel
and 4 contributors

NAME

Lab::Data::Analysis - Analyze data from 'Trace' files

VERSION

Version 0.01

SYNOPSIS

    use Lab::Data::Analysis;

    my $t = Lab::Data::Analysis->new();

    $t->open($tracefile);

    RANDOM ACCESS:

    $t->MakeIndex();
 
    $t->PrintIndex();

    my $fhdr = $t->ReadFileHeader();

    my $rhdr = $t->ReadRunHeader(run=>3);

    my $ev = $t->ReadEvent(run=>3, event=>77);

    
    ... do analysis...



    SEQUENTIAL:

    my $fhdr = $t->ReadFileHeader();

    while (defined($rhdr = $t->ReadRunHeader()) {
       
        print "Run: ",$rhdr->{RUN},"\n";

        while (defined($ev = $t->ReadEvent()) {
             
            print "Event: ", $ev->{EVENT}, "\n";

            do analysis...
        }
    }


    Note that "random access" and "sequential" can be mixed,
    if you keep track of the file position. 

SUBROUTINES/METHODS

new

my $t = Lab::Data::Analysis->new(); # do 'open' later

my $t = Lab::Data::Analysis->new($tracefile);

my $t = Lab::Data::Analysis->new( file => $tracefile, ...options );

open

$t->open($file);

$t->open(file=>$file, ...);

Open a trace file for reading.

rewind

$t->rewind();

Position to beginning of file for sequential access.

Not sure that this is really needed: ReadFileHeader() automatically goes to the beginning of the file; ReadRunHeader(run=>firstrun) should read the header of the first run in the file, and leave the file positioned to start reading events.

MakeIndex

$t->MakeIndex();

Compile an index of Runs/Events in a tracefile, for later use.

Be warned: this may take some time for large files.

PrintIndex

$t->PrintIndex();

Print an index of the tracefile, showing locations of runs/events, etc.

ReadEvent

my $event = $t->ReadEvent();

my $event = $t->ReadEvent($stream);

my $event = $t->ReadEvent([$stream1[, $stream2...]]);

my $event = $t->ReadEvent(stream=>$stream);

my $event = $t->ReadEvent(stream=>[$stream1[,$stream2...]]);

Also can use a no_global=>1 option to exclude the 'global' (stream=0) stream, which just has comments. Adding run=>$run, event=>$event parameters causes FindEvent(run=>..., event=>...) to be called before reading the event.

Read an event, starting at the current file position. This may involve skipping over (and ignoring) lines until reaching the next EVENT line. The event is returned in a hash structure, containing the raw data in all data streams for the event, up to the following EVENT marker, the "STOP RUN" marker, or the end of the file.

Returns 'undef' if no more events remain in the file.

Data streams can be selected by passing $stream parameter, and multiple streams by passing reference to an array.

ReadFileHeader

my $hdr = $t->ReadFileHeader([$shift]);

my $hdr = $t->ReadFileHeader(shift=>$shift);

Read the header of the data file (before the start of the first run), and store in a hashref. If '$shift' is true (=1,'yes', 'true') then leave the file positioned after the file header. The 'shift' parameter is usually not needed, because ReadRunHeader will just read from the start of the file to the first run.

If 'shift' is not specified, then the file position is restored to where it was prior to the ReadFileHeader call, which can be useful if the file header is read later in the analysis.

ReadRunHeader

my $rhdr = $t->ReadRunHeader();

my $rhdr = $t->ReadRunHeader($run);

my $rhdr = $t->ReadRunHeader(run=>$run);

Reads the header information between the start of run and the first event. If the run number is not given, reads from the current file position until the run is found. Returns undef if the file is not found.

Returns a hashref with the information, and leaves the file positioned at the first event of the run.

FindEvent

$t->FindEvent($run,$event);

$t->FindEvent(run=>$run, event=>$event);

Find the specified event in the specified run (if run=undef or <=0, then use current run). Returns undef if the event is not found, otherwise returns the file position and leaves the file positioned so that ReadEvent will read the specified event.

If event is undefined, defaults to the 'next event'; for files that have been indexed event=-1 returns the LAST event (-2 next to last, etc). Without an index event < 0 is treated as event=0.

Note that this routine is MUCH more efficient if an index is created.

PrintDefaultAnalyzer

$t->PrintDefaultAnalyzer([$stream, $stream,...]);

$t->PrintDefaultAnalyzer(stream=>[$stream1,$stream2,...]);

Print the 'default' analyzer modules for the selected streams (default = 'all streams'). If the file header has not yet been read, this routine reads the file header to get the setup information about the data streams.

ConnectAnalyzer

$t->ConnectAnalyzer([[$stream],$module]);

$t->ConnectAnalyzer(stream=>$stream, module=>$module);

Connect an analysis module to a data stream. If the stream is unspecified, try to connect to all data streams. If the module is unspecified, try to use a 'default' module for the stream. Note that connecting multiple analysis modules to a stream results in the module being called in sequence, using the result from the previous analysis module.

Default modules are in Lab::Data::Analysis:: ...

Analyze

my $ev = $t->Analyze($ev[,$options,[,$stream1,$stream2,...]);

my $ev = $t->Analyze(event=>$ev[, stream=>$stream1][,analyzeroptions=>..]);

my $ev = $t->Analyze(event=>$ev[, stream=>[$stream1,$stream2,...] [, analyzeroptions=>]);

runs the analysis chain on the given event, for the given streams (default: all streams). The event is returned with analysis data added to the hashref. Options for the analyzer (in the key=>value form) can be passed if the hash calling form is used.