--- loncom/homework/functionplotresponse.pm 2010/10/29 19:18:48 1.17
+++ loncom/homework/functionplotresponse.pm 2010/11/06 14:37:24 1.23
@@ -1,7 +1,7 @@
# LearningOnline Network with CAPA
# option list style responses
#
-# $Id: functionplotresponse.pm,v 1.17 2010/10/29 19:18:48 www Exp $
+# $Id: functionplotresponse.pm,v 1.23 2010/11/06 14:37:24 www Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -363,7 +363,7 @@ sub end_splinerule {
#
-#
+#
#
# Unfortunately, GeoGebra seems to want all splines after everything else, so we need to store them
#
@@ -371,15 +371,19 @@ sub start_spline {
my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
my $result='';
if ($target eq 'web') {
- my $label=&Apache::lonxml::get_param('label',$parstack,$safeeval);
+ my $label=&Apache::lonxml::get_param('index',$parstack,$safeeval);
$Apache::functionplotresponse::counter++;
if ($label=~/\W/) {
- &Apache::lonxml::warning(&mt('Spline labels should only contain alphanumeric characters.'));
+ &Apache::lonxml::warning(&mt('Spline indices should only contain alphanumeric characters.'));
}
$label=~s/\W//gs;
- unless ($label) { $label='S'.$Apache::functionplotresponse::counter; }
+ unless ($label) {
+ $label='S'.$Apache::functionplotresponse::counter;
+ } else {
+ $label='S'.$label;
+ }
if ($Apache::functionplotresponse::splineorder{$label}) {
- &Apache::lonxml::error(&mt('Spline labels must be unique.'));
+ &Apache::lonxml::error(&mt('Spline indices must be unique.'));
}
my $order=&Apache::lonxml::get_param('order',$parstack,$safeeval);
@@ -404,7 +408,7 @@ sub start_spline {
$Apache::functionplotresponse::splinescaley{$label}=$sy;
} elsif ($target eq 'edit') {
$result=&Apache::edit::tag_start($target,$token,'Spline').
- &Apache::edit::text_arg('Label:','label',
+ &Apache::edit::text_arg('Index:','index',
$token,'4').' '.
&Apache::edit::select_arg('Order:','order',
['2','3','4','5','6','7','8','9'],$token).' '.
@@ -419,7 +423,7 @@ sub start_spline {
&Apache::edit::end_row();
} elsif ($target eq 'modified') {
my $constructtag=&Apache::edit::get_new_args($token,$parstack,
- $safeeval,'label','order','initx','inity',
+ $safeeval,'index','order','initx','inity',
'scalex','scaley');
if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
}
@@ -499,6 +503,144 @@ sub d2dt2_cubic_hermite {
}
#
+# Array index calculation
+#
+sub array_index {
+ my ($xmin,$xmax,$x)=@_;
+ return int(($x-$xmin)/($xmax-$xmin)*200.+0.5);
+}
+
+#
+# Actual x-value of array index
+#
+
+sub index_x {
+ my ($xmin,$xmax,$i)=@_;
+ return $i*($xmax-$xmin)/200.+$xmin;
+}
+
+#
+# Assume function to be linear between array points
+# Return the two indices and the scale factor
+#
+
+sub indices_scale {
+ my ($xmin,$xmax,$x)=@_;
+ my $i=&array_index($xmin,$xmax,$x);
+ my $xr=&index_x($xmin,$xmax,$i);
+ if ($xr<$x) {
+# Desired x is right of array index
+ if ($i>=200) { return (200,200,0); }
+ return($i,$i+1,200.*($x-$xr)/($xmax-$xmin));
+ } elsif ($xr>$x) {
+# Desired x is left of array index
+ if ($i<=0) { return (0,0,0); }
+ return($i-1,$i,1.-200.*($xr-$x)/($xmax-$xmin));
+ } else {
+# Desired x is at array index (unlikely, but ...)
+ if ($i>=200) { return (200,200,0); }
+ if ($i<=0) { return (0,0,0); }
+ return ($i,$i,0);
+ }
+}
+
+#
+# Function value
+#
+
+sub func_val {
+ my ($xmin,$xmax,$x)=@_;
+ my ($il,$ih,$factor)=&indices_scale($xmin,$xmax,$x);
+ my $fl=$Apache::functionplotresponse::func[$il];
+ my $fh=$Apache::functionplotresponse::func[$ih];
+ unless (defined($fl) || defined($fh)) { return undef; }
+ unless (defined($fl)) { return $fh; }
+ unless (defined($fh)) { return $fl; }
+ return $fl+$factor*($fh-$fl);
+}
+
+#
+# First derivative
+#
+
+sub dfuncdx_val {
+ my ($xmin,$xmax,$x)=@_;
+ my ($il,$ih,$factor)=&indices_scale($xmin,$xmax,$x);
+ my $fl=$Apache::functionplotresponse::dfuncdx[$il];
+ my $fh=$Apache::functionplotresponse::dfuncdx[$ih];
+ unless (defined($fl) || defined($fh)) { return undef; }
+ unless (defined($fl)) { return $fh; }
+ unless (defined($fh)) { return $fl; }
+ return $fl+$factor*($fh-$fl);
+}
+
+#
+# Second derivative
+#
+
+sub d2funcdx2_val {
+ my ($xmin,$xmax,$x)=@_;
+ my ($il,$ih,$factor)=&indices_scale($xmin,$xmax,$x);
+ my $fl=$Apache::functionplotresponse::d2funcdx2[$il];
+ my $fh=$Apache::functionplotresponse::d2funcdx2[$ih];
+ unless (defined($fl) || defined($fh)) { return undef; }
+ unless (defined($fl)) { return $fh; }
+ unless (defined($fh)) { return $fl; }
+ return $fl+$factor*($fh-$fl);
+}
+
+#
+# Populate the arrays
+#
+
+sub populate_arrays {
+ my ($id,$xmin,$xmax)=@_;
+ for (my $i=0; $i<=200; $i++) {
+ $Apache::functionplotresponse::func[$i]=undef;
+ $Apache::functionplotresponse::dfuncdx[$i]=undef;
+ $Apache::functionplotresponse::d2funcd2x[$i]=undef;
+ }
+ unless ($xmax>$xmin) { return 'no_func'; }
+# Run over all splines in response
+ foreach my $label (split(/\,/,$env{"form.HWVAL_AllSplines_$id"})) {
+ my $xiold=-1;
+# Run over all points in spline
+ for (my $i=1; $i<$env{"form.HWVAL_SplineOrder_".$id."_".$label}; $i++) {
+ my $ni=$i+1;
+ my @xparms=($env{'form.HWVAL_'.$id.'_'.$label.'P'.$i.'_x'},
+ $env{'form.HWVAL_'.$id.'_'.$label.'S'.$i.'_x'},
+ $env{'form.HWVAL_'.$id.'_'.$label.'P'.$ni.'_x'},
+ $env{'form.HWVAL_'.$id.'_'.$label.'S'.$ni.'_x'});
+ my @yparms=($env{'form.HWVAL_'.$id.'_'.$label.'P'.$i.'_y'},
+ $env{'form.HWVAL_'.$id.'_'.$label.'S'.$i.'_y'},
+ $env{'form.HWVAL_'.$id.'_'.$label.'P'.$ni.'_y'},
+ $env{'form.HWVAL_'.$id.'_'.$label.'S'.$ni.'_y'});
+# Run in small steps over spline parameter
+ for (my $t=0; $t<=1; $t+=0.00025) {
+ my $xi=&array_index($xmin,$xmax,&cubic_hermite($t,@xparms));
+ if ($xi<$xiold) { return 'no_func'; }
+ if (($xi>$xiold) && ($xi>=0) && ($xi<=200)) {
+ if (defined($Apache::functionplotresponse::func[$xi])) { return 'no_func'; }
+ $xiold=$xi;
+# Function value
+ $Apache::functionplotresponse::func[$xi]=&cubic_hermite($t,@yparms);
+# dy/dx=dy/dt/(dx/dt)
+ my $dxdt=&ddt_cubic_hermite($t,@xparms);
+ if ($dxdt) {
+ $Apache::functionplotresponse::dfuncdx[$xi]=&ddt_cubic_hermite($t,@yparms)/$dxdt;
+ }
+# d^2y/dx^2
+ my $d2xdt2=&d2dt2_cubic_hermite($t,@xparms);
+ if ($d2xdt2) {
+ $Apache::functionplotresponse::d2funcd2x[$xi]=&d2dt2_cubic_hermite($t,@yparms)/$d2xdt2;
+ }
+ }
+ }
+ }
+ }
+}
+
+#
# Implentation of
#
@@ -525,13 +667,13 @@ sub start_functionplotresponse {
# Parameters of
my $xmin=&Apache::lonxml::get_param('xmin',$parstack,$safeeval);
- $xmin=($xmin?$xmin:-10);
+ $xmin=(defined($xmin)?$xmin:-10);
my $xmax=&Apache::lonxml::get_param('xmax',$parstack,$safeeval);
- $xmax=($xmax?$xmax:10);
+ $xmax=(defined($xmax)?$xmax:10);
my $ymin=&Apache::lonxml::get_param('ymin',$parstack,$safeeval);
- $ymin=($ymin?$ymin:-10);
+ $ymin=(defined($ymin)?$ymin:-10);
my $ymax=&Apache::lonxml::get_param('ymax',$parstack,$safeeval);
- $ymax=($ymax?$ymax:10);
+ $ymax=(defined($ymax)?$ymax:10);
my $xaxisvisible=(&Apache::lonxml::get_param('xaxisvisible',$parstack,$safeeval)=~/on|true|yes|1/i?'true':'false');
my $yaxisvisible=(&Apache::lonxml::get_param('yaxisvisible',$parstack,$safeeval)=~/on|true|yes|1/i?'true':'false');
my $gridvisible=(&Apache::lonxml::get_param('gridvisible',$parstack,$safeeval)=~/on|true|yes|1/i?'true':'false');
@@ -612,7 +754,17 @@ sub end_functionplotresponse {
#
# Actually grade
#
- my $ad='INCORRECT';
+ my $xmin=&Apache::lonxml::get_param('xmin',$parstack,$safeeval);
+ $xmin=(defined($xmin)?$xmin:-10);
+ my $xmax=&Apache::lonxml::get_param('xmax',$parstack,$safeeval);
+ $xmax=(defined($xmax)?$xmax:10);
+ my $ad;
+ if (&populate_arrays($internalid,$xmin,$xmax) eq 'no_func') {
+ $ad='NOT_FUNCTION';
+ } else {
+ $ad='INCORRECT';
+ }
+
#
# Store grading info
#