- Make diff() care for evaluating stuff.

[ginac.git] / ginac / function.pl

diff --git a/ginac/function.pl b/ginac/function.pl
index f1b57f13db56419afbb78b6e9326c91fdd9e75dc..6dbee8bb1039b6385f016555ed24f2ced46c351e 100755 (executable)
--- a/ginac/function.pl
+++ b/ginac/function.pl
@@ -59,8 +59,8 @@ $typedef_evalf_funcp=generate(
 'typedef ex (* evalf_funcp_${N})(${SEQ1});'."\n",
 'const ex &','');
 
-$typedef_diff_funcp=generate(
-'typedef ex (* diff_funcp_${N})(${SEQ1}, unsigned);'."\n",
+$typedef_derivative_funcp=generate(
+'typedef ex (* derivative_funcp_${N})(${SEQ1}, unsigned);'."\n",
 'const ex &','');
 
 $typedef_series_funcp=generate(
@@ -73,7 +73,7 @@ $constructors_interface=generate(
 
 $register_new_interface=generate(
 '    static unsigned register_new(const char * nm, eval_funcp_${N} e,'."\n".
-'                                 evalf_funcp_${N} ef=0, diff_funcp_${N} d=0, series_funcp_${N} s=0);'.
+'                                 evalf_funcp_${N} ef=0, derivative_funcp_${N} d=0, series_funcp_${N} s=0);'.
 "\n",'','');
 
 $constructors_implementation=generate(
@@ -103,7 +103,7 @@ END_OF_EVALF_SWITCH_STATEMENT
 $diff_switch_statement=generate(
     <<'END_OF_DIFF_SWITCH_STATEMENT','seq[${N}-1]','');
     case ${N}:
-        return ((diff_funcp_${N})(registered_functions()[serial].d))(${SEQ1},diff_param);
+        return ((derivative_funcp_${N})(registered_functions()[serial].d))(${SEQ1},diff_param);
         break;
 END_OF_DIFF_SWITCH_STATEMENT
 
@@ -122,10 +122,10 @@ END_OF_SERIES_SWITCH_STATEMENT
 $register_new_implementation=generate(
     <<'END_OF_REGISTER_NEW_IMPLEMENTATION','','');
 unsigned function::register_new(const char * nm, eval_funcp_${N} e,
-                                 evalf_funcp_${N} ef, diff_funcp_${N} d, series_funcp_${N} s)
+                                 evalf_funcp_${N} ef, derivative_funcp_${N} d, series_funcp_${N} s)
 {
     registered_function_info rfi={nm,${N},0,eval_funcp(e),
-                                  evalf_funcp(ef),diff_funcp(d),series_funcp(s)};
+                                  evalf_funcp(ef),derivative_funcp(d),series_funcp(s)};
     registered_functions().push_back(rfi);
     return registered_functions().size()-1;
 }
@@ -171,31 +171,31 @@ $interface=<<END_OF_INTERFACE;
 
 #include "exprseq.h"
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 
 // the following lines have been generated for max. ${maxargs} parameters
 $declare_function_macro_namespace
 // end of generated lines
 
-#else // ndef NO_GINAC_NAMESPACE
+#else // ndef NO_NAMESPACE_GINAC
 
 // the following lines have been generated for max. ${maxargs} parameters
 $declare_function_macro_no_namespace
 // end of generated lines
 
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 
 #define REGISTER_FUNCTION(NAME,E,EF,D,S) \\
 const unsigned function_index_##NAME=GiNaC::function::register_new(#NAME,E,EF,D,S);
 
-#else // ndef NO_GINAC_NAMESPACE
+#else // ndef NO_NAMESPACE_GINAC
 
 #define REGISTER_FUNCTION(NAME,E,EF,D,S) \\
 const unsigned function_index_##NAME=function::register_new(#NAME,E,EF,D,S);
 
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 #define BEGIN_TYPECHECK \\
 bool automatic_typecheck=true;
@@ -205,21 +205,21 @@ if (!is_ex_exactly_of_type(VAR,TYPE)) { \\
     automatic_typecheck=false; \\
 } else
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 
 #define TYPECHECK_INTEGER(VAR) \\
 if (!(VAR).info(GiNaC::info_flags::integer)) { \\
     automatic_typecheck=false; \\
 } else
 
-#else // ndef NO_GINAC_NAMESPACE
+#else // ndef NO_NAMESPACE_GINAC
 
 #define TYPECHECK_INTEGER(VAR) \\
 if (!(VAR).info(info_flags::integer)) { \\
     automatic_typecheck=false; \\
 } else
 
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 #define END_TYPECHECK(RV) \\
 {} \\
@@ -227,21 +227,21 @@ if (!automatic_typecheck) { \\
     return RV.hold(); \\
 }
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 namespace GiNaC {
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 class function;
 
 typedef ex (* eval_funcp)();
 typedef ex (* evalf_funcp)();
-typedef ex (* diff_funcp)();
+typedef ex (* derivative_funcp)();
 typedef ex (* series_funcp)();
 
 // the following lines have been generated for max. ${maxargs} parameters
 $typedef_eval_funcp
 $typedef_evalf_funcp
-$typedef_diff_funcp
+$typedef_derivative_funcp
 $typedef_series_funcp
 // end of generated lines
 
@@ -251,7 +251,7 @@ struct registered_function_info {
     unsigned options;
     eval_funcp e;
     evalf_funcp ef;
-    diff_funcp d;
+    derivative_funcp d;
     series_funcp s;
 };
 
@@ -296,11 +296,11 @@ public:
     ex expand(unsigned options=0) const;
     ex eval(int level=0) const;
     ex evalf(int level=0) const;
-    ex diff(const symbol & s) const;
     ex series(const symbol & s, const ex & point, int order) const;
     ex thisexprseq(const exvector & v) const;
     ex thisexprseq(exvector * vp) const;
 protected:
+    ex derivative(const symbol & s) const;
     int compare_same_type(const basic & other) const;
     bool is_equal_same_type(const basic & other) const;
     unsigned return_type(void) const;
@@ -311,7 +311,7 @@ protected:
     
     // non-virtual functions in this class
 protected:
-    ex pdiff(unsigned diff_param) const; // partial differentiation
+    ex pderivative(unsigned diff_param) const; // partial differentiation
     static vector<registered_function_info> & registered_functions(void);
 public:
     // the following lines have been generated for max. ${maxargs} parameters
@@ -327,26 +327,26 @@ protected:
 
 // utility macros
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 
 #define is_ex_the_function(OBJ, FUNCNAME) \\
     (is_ex_exactly_of_type(OBJ, function) && static_cast<GiNaC::function *>(OBJ.bp)->getserial() == function_index_##FUNCNAME)
 
-#else // ndef NO_GINAC_NAMESPACE
+#else // ndef NO_NAMESPACE_GINAC
 
 #define is_ex_the_function(OBJ, FUNCNAME) \\
     (is_ex_exactly_of_type(OBJ, function) && static_cast<function *>(OBJ.bp)->getserial() == function_index_##FUNCNAME)
 
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 // global constants
 
 extern const function some_function;
 extern const type_info & typeid_function;
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 } // namespace GiNaC
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 #endif // ndef __GINAC_FUNCTION_H__
 
@@ -385,12 +385,13 @@ $implementation=<<END_OF_IMPLEMENTATION;
 #include "function.h"
 #include "ex.h"
 #include "archive.h"
+#include "inifcns.h"
 #include "utils.h"
 #include "debugmsg.h"
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 namespace GiNaC {
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 GINAC_IMPLEMENT_REGISTERED_CLASS(function, exprseq)
 
@@ -664,6 +665,34 @@ ${series_switch_statement}
 
 // protected
 
+
+/** Implementation of ex::diff() for functions. It applies the chain rule,
+ *  except for the Order term function.
+ *  \@see ex::diff */
+ex function::derivative(const symbol & s) const
+{
+    ex result;
+    
+    if (serial==function_index_Order) {
+        // Order Term function only differentiates the argument
+        return Order(seq[0].diff(s));
+    } else {
+        // Chain rule
+        ex arg_diff;
+        for (unsigned i=0; i!=seq.size(); i++) {
+            arg_diff = seq[i].diff(s);
+            // We apply the chain rule only when it makes sense.  This is not
+            // just for performance reasons but also to allow functions to
+            // throw when differentiated with respect to one of its arguments
+            // without running into trouble with our automatic full
+            // differentiation:
+            if (!arg_diff.is_zero())
+                result += pderivative(i)*arg_diff;
+        }
+    }
+    return result;
+}
+
 int function::compare_same_type(const basic & other) const
 {
     GINAC_ASSERT(is_of_type(other, function));
@@ -712,19 +741,19 @@ unsigned function::return_type_tinfo(void) const
 
 // protected
 
-ex function::pdiff(unsigned diff_param) const // partial differentiation
+ex function::pderivative(unsigned diff_param) const // partial differentiation
 {
     GINAC_ASSERT(serial<registered_functions().size());
     
     if (registered_functions()[serial].d==0) {
-        throw(std::logic_error(string("function::pdiff(") + registered_functions()[serial].name + "): no diff function defined"));
+        throw(std::logic_error(string("function::pderivative(") + registered_functions()[serial].name + "): no diff function defined"));
     }
     switch (registered_functions()[serial].nparams) {
         // the following lines have been generated for max. ${maxargs} parameters
 ${diff_switch_statement}
         // end of generated lines
     }        
-    throw(std::logic_error("function::pdiff(): no diff function defined"));
+    throw(std::logic_error("function::pderivative(): no diff function defined"));
 }
 
 vector<registered_function_info> & function::registered_functions(void)
@@ -752,9 +781,9 @@ $register_new_implementation
 const function some_function;
 const type_info & typeid_function=typeid(some_function);
 
-#ifndef NO_GINAC_NAMESPACE
+#ifndef NO_NAMESPACE_GINAC
 } // namespace GiNaC
-#endif // ndef NO_GINAC_NAMESPACE
+#endif // ndef NO_NAMESPACE_GINAC
 
 END_OF_IMPLEMENTATION