[WWcvs] pg: Added a final_period=>1 flag for PiecewiseFunction objects so that the final condition will include a period (so that you

[dpvc v. a. <we...@ma...>]

Log Message:
-----------
Added a final_period=>1 flag for PiecewiseFunction objects so that the
final condition will include a period (so that you can put a piecewise
function as the last thing in a sentence).

Modified Files:
--------------
    pg/macros:
        contextPiecewiseFunction.pl

Revision Data
-------------
Index: contextPiecewiseFunction.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/contextPiecewiseFunction.pl,v
retrieving revision 1.9
retrieving revision 1.10
diff -Lmacros/contextPiecewiseFunction.pl -Lmacros/contextPiecewiseFunction.pl -u -r1.9 -r1.10
--- macros/contextPiecewiseFunction.pl
+++ macros/contextPiecewiseFunction.pl
@@ -64,12 +64,25 @@
 	
 	Context()->texStrings;
 	BEGIN_TEXT
-	Suppose \(f(x)=$f\).  Then \(f($a)\) = \{ans_rule(20)\}.
+	If \[f(x)=$f\] then \(f($a)\) = \{ans_rule(20)\}.
 	END_TEXT
 	Context()->normalStrings;
 	
 	ANS($f->eval(x=>$a)->cmp);
 
+Normally when you use a piecewise function at the end of a sentence,
+the period is placed at the end of the last case.  Since
+
+	\[ f(x) = $f \].
+
+would put the period centered at the right-hand side of the function,
+this is not what is desired.  To get a period at the end of the last
+case, use
+
+	\[ f(x) = \{$f->with(final_period=>1)\} \]
+
+instead.
+
 =cut
 
 loadMacros("MathObjects.pl");
@@ -741,12 +754,13 @@
 #
 sub string {
   my $self = shift; my @cases = ();
+  my $period = ($self->{final_period} ? "." : "");
   foreach my $If (@{$self->{data}}) {
     my ($I,$f) = @{$If};
     push(@cases,$f->string." if ".$I->string);
   }
   push(@cases,$self->{otherwise}->string) if defined $self->{otherwise};
-  join(" else\n",@cases);
+  join(" else\n",@cases) . $period;
 }
 
 #
@@ -754,13 +768,14 @@
 #
 sub TeX {
   my $self = shift; my @cases = ();
+  my $period = ($self->{final_period} ? "." : "");
   foreach my $If (@{$self->{data}}) {
     my ($I,$f) = @{$If};
     push(@cases,'\displaystyle{'.$f->TeX."}&\\text{if}\\ ".$I->TeX);
   }
   if (scalar(@cases)) {
     push(@cases,'\displaystyle{'.$self->{otherwise}->TeX.'}&\text{otherwise}') if defined $self->{otherwise};
-    return '\begin{cases}'.join('\cr'."\n",@cases).'\end{cases}';
+    return '\begin{cases}'.join('\cr'."\n",@cases).$period.'\end{cases}';
   } else {
     return $self->{otherwise}->TeX;
   }