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C++ classes for symbolic manipulation 
The classes provided by GiNaC allow for symbolic expressions to be expressed and manipulated.
There are three classes provided in GiNaC which made are available in D using SWIG.
- symbol is an object initialised to a string. e.g.
| symbol x = new symbol("x");
symbol y = new symbol("y"); |
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- ex is an expression involving one or more symbols. e.g.
| ex exx = new ex(x);
ex exy = new ex(y); |
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- lst is a list of expressions. e.g.
| lst l = new lst(exx,exy); |
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An object of class lst can be used to initalise an expression from a string e.g.
| ex e11 = new ex("x+y",l); |
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where l provides a list of the symbols in the expression.
Features used
The features used here are the same as described in /Examples/Qdmath . The interface contains a lot of code to implement overloaded operators. The implementation of this in D is considerably easier than some other languages, such as Ruby and python.
Code to be wrapped
This is contained in the header files for GiNaC. The current version uses GiNaC 1.1.4. This needs to be upadated to the current version.
Interface file
This is rather long so I will not put it here. It is getting more urgent to set up a location for distribution of these files to those who would like them. It was not a long task to adapt the interface file which I already used for Ruby.
Run SWIG
The output is the following files
- ginacd.d
- classsymbol.d
- classex.d
- classlst.d
- ginacdPINVOKE.d
- ginacd_wrap.cxx
Example application
runginacd.d
| // Experiments with GiNaC for D..
// Imports conversion stuff from C
import std.string;
import std.intrinsic;
import std.math;
import classsymbol;
int main(char[][] args)
{
printf("GiNaC for D\n");
symbol x = new symbol("x");
printf("x = %s\n",x.str());
symbol y = new symbol("y");
printf("y = %s\n",y.str());
ex exx = new ex(x);
ex exy = new ex(y);
lst l = new lst(exx,exy);
printf("l = %s\n",l.str());
ex e0 = new ex(0);
ex e1 = new ex(1);
printf("e1 = %s\n",e1.str());
ex e11 = new ex("x+y",l);
printf("e11 = %s\n",e11.str());
printf("e1 + e11 = %s\n",(e1+e11).str());
printf("e11 - e1 = %s\n",(e11-e1).str());
printf("e11 * e11 = %s\n",(e11*e11).str());
printf("e11 / e11 = %s\n",(e11/e11).str());
printf("x + y = %s\n",(x+y).str());
printf("e1 + y = %s\n",(e1+y).str());
printf("x + e1 = %s\n",(x+e1).str());
printf("1 + e11 = %s\n",(1+e11).str());
printf("1.5 + e11 = %s\n",(1.5+e11).str());
printf("2*x + 3*y = %s\n",(2*x+3*y).str());
ex es = 1 + 3*x/(x+y);
printf("es = 1 + 3*x/(x+y) = %s\n",es.str());
printf("es.normal() = %s\n",es.normal().str());
printf("End of tests\n");
return 0;
} |
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Linux
| dmd -c runginacd.d
dmd -c ginacd.d
dmd -c classsymbol.d
dmd -c classex.d
dmd -c classlst.d
g++ -c ginacd_wrap.cxx
g++ runginacd.o -orunginacd ginacd.o classsymbol.o classex.o classlst.o ginacd_wrap.o -lginac -lphobos -lpthread -lm |
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Windows
GiNaC is not available for Windows.
Output
| GiNaC for D
x = x
y = y
l = {x,y}
e1 = 1
e11 = y+x
e1 + e11 = 1+y+x
e11 - e1 = -1+y+x
e11 * e11 = (y+x)^2
e11 / e11 = 1
x + y = y+x
e1 + y = 1+y
x + e1 = 1+x
1 + e11 = 1+y+x
1.5 + e11 = 1.5+y+x
2*x + 3*y = 3*y+2*x
es = 1 + 3*x/(x+y) = 1+3*(y+x)^(-1)*x
es.normal() = (y+x)^(-1)*(y+4*x)
End of tests |
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C++ classes for symbolic manipulation