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D.15.12.13 difformToString
Procedure from library difform.lib (see difform_lib).
- Usage:
- difformToString(df,#); df difform,# list
- Return:
- df as a string, sorted by a given ordering on the generators (standard: the ordering chosen for the differential algebra)
- Remarks:
- The differential form is decomposed via difformCoef, the coefficient list is sorted
and then the string is built as concatenation of coefficients and generators
- Note:
- to get a string, respecting a certain monomial ordering on the generators, use:
- #[1] = 'gen'
- #[2]: a monomial ordering as string
- #[3]: an optional weight vector
Example:
| | LIB "difform.lib";
ring R = 0,(x,y,z,a,b),ds;
diffAlgebra();
==> // The differential algebra Omega_R was constructed and the differential \
forms dx, dy, dz, da, db are available.
difform df = 3*x*dx -2*db + 24*a*dy - y*dx*dy*db + 12*dx*dy*dz - dz*dy*da*db + 3 + 12*x*dx - 1/77*da*dx;
//////////////////////////////////////////////////////////////////////////////////
// String sorted with respect to the monomial order on the differential algebra //
//////////////////////////////////////////////////////////////////////////////////
string df_str = difformToString(df);
print(df_str);
==> dy*dz*da*db+12*dx*dy*dz+(-y)*dx*dy*db+1/77*dx*da+15x*dx+24a*dy+(-2)*db+3
/////////////////////////////////////////////////////////
// String sorted with respect to the weighted order wp //
/////////////////////////////////////////////////////////
df_str = difformToString(df,"gen","wp",intvec(-1,-1,-1,1,1));
print(df_str);
==> (-2)*db+dy*dz*da*db+1/77*dx*da+3+(-y)*dx*dy*db+15x*dx+24a*dy+12*dx*dy*dz
kill Omega_R,df,df_str,dx,dy,dz,da,db;
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See also:
difformGenToString;
difformPrint.
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