[GT] SVN Commit r563 - trunk/GT/Indicators/Generic

[GeniusTrader SVN <raphael AT geniustrader.org>]

Author: ras
Date: 2008-03-12 06:31:41 +0100 (Wed, 12 Mar 2008)
New Revision: 563

Modified:
   trunk/GT/Indicators/Generic/ByName.pm
Log:
fixes some issues with object names changing after it is
generated by ArgsTrees::parse_args



Modified: trunk/GT/Indicators/Generic/ByName.pm
===================================================================
--- trunk/GT/Indicators/Generic/ByName.pm	2008-03-11 06:36:12 UTC (rev 562)
+++ trunk/GT/Indicators/Generic/ByName.pm	2008-03-12 05:31:41 UTC (rev 563)
@@ -1,9 +1,12 @@
 package GT::Indicators::Generic::ByName;
 
 # Copyright 2000-2002 Rapha�Hertzog, Oliver Bossert
+# Corrections and documention Copyright 2008 Thomas Weigert
 # This file is distributed under the terms of the General Public License
 # version 2 or (at your option) any later version.
 
+# $Id$
+
 # Standards-Version: 1.0
 
 use strict;
@@ -22,17 +25,40 @@
 
 =head2 DESCRIPTION
 
-Sometimes when you create expressions to be passed as parameters
-to other indicators you need to include a reference to a value
-which is calculated by the indicator in which you are. But it you give
-name of the current indicator you may have an infinite recursion
-because of the dependencies.
+Sometimes, during the computation of an indicator, one needs to reference
+the current value of a series that is being computed by this indicator.
+If the current indicator is used explicity, an infinite recursion arises
+due to the dependency mechanism.
 
-This indicator can help you break that loop by using an indirection
-level. This indicator is nothing more than an alias of a another value
-calculated by another indicator. Just give as first parameter the name
-of the value to use and you're done.
+This indicator resolves the recursion. This indicator is nothing more than
+an alias of a seried calculated by an indicator. Just give as first parameter
+the name of the value to use.
 
+This indicator is used when, during the calculation of an indicator,
+an intermediate series wants to leverage another intermediate series
+or an output value.
+
+For example,
+    $self->{'sma1'} = GT::Indicators::SMA->new([ $self->{'args'}->get_arg_names(1), $self->{'args'}->get_arg_names(2) ]);
+    $self->{'sma2'} = GT::Indicators::SMA->new([ $self->{'args'}->get_arg_names(1), "{I:Generic:ByName " . $self->{'sma1'}->get_name . "}" ]);
+
+The first line defines an intermediate series which smoothes the
+second parameter. The second line takes that series and applies 
+smoothing again. Similarly, the following applies smoothing to
+the first output value.
+    $self->{'sma3'} = GT::Indicators::SMA->new([ $self->{'args'}->get_arg_names(1), "{I:Generic:ByName " . $self->get_name(0) . "}" ]);
+
+Care has to be taken that I:Generic:ByName is in fact given the
+name of an indicator, lest that series will not be found. The get_name
+method will always retrieve the name of a series. The parsable syntax
+does yield a name also.
+
+***FIXME***
+The name as generated by the ArgsTree::parse_args is rather
+brittle and needs to be fixed up as indicated in the comments
+embedded in this modules code. Additional problems might exist.
+
+
 =cut
 
 sub new {
@@ -40,7 +66,22 @@
     my $class = ref($type) || $type;
     my $self = { };
     no strict "refs";
-    $self->{'args'}->[0] = join(" ", @{$args});
+    # Note: Do not add any cruft (e.g., whitespace) when joining the
+    # argument list, otherwise the constructed name will differ from
+    # the name of the referenced series.
+    #$self->{'args'}->[0] = join('', @{$args});
+
+    my $out =  '';
+    foreach (@{$args}) {
+      $out .= $_;
+      $out .= ' ' if ($_ =~ /[a-zA-Z0-9]$/o);
+    }
+    # Note: line 333 of ArgsTree.pm inserts extra \s before opening brace
+    # However, when CacheValues are set, these extra \s are not present in name
+    # Remove. 
+    $out =~ s/(\s)+/$1/go;
+    $self->{'args'}->[0] = $out;
+
     return manage_object(\
AT
{"$class\::NAMES"}, $self, $class, $self->{'args'}, $key);
 }
 
@@ -57,19 +98,11 @@
     my @pars = ();
     my $parname = $self->{'args'}->[0];
 
-    if ($indic->is_available($parname, $i)) {
-	$indic->set($name, $i, $indic->get($parname, $i) );
-	return;
-    }
-    #print "Failed to retrieve $parname for day $i.\n";
-    $parname =~ s/\s+{/{/g;
-    $parname =~ s/}\s+/}/g;
-    #print "Trying instead $parname\n";
-    if ($indic->is_available($parname, $i)) {
-	$indic->set($name, $i, $indic->get($parname, $i) );
-	return;
-    }
-    #print "Failed as well.\n";
+    #print "ByName($i): $parname = " . (($indic->is_available($parname, $i))?$indic->get($parname, $i):'') . "\n";
+
+    $indic->set($name, $i, $indic->get($parname, $i))
+     if ($indic->is_available($parname, $i));
+
 }
 
 1;