I have made a series of long computations. One computation is faster but requires me to solve the numerical root of a polynomial and another computation is slower but more exact and the computations are mostly symbolic. To compare these computation I subtract the result to see if it becomes zero. Giacpy seems to have trouble with it (Xcas has only trouble with it if I use the "simplify" command, but writing the whole subtracted expression will yield 0). You can reproduce the problem with the following short code
Code : Tout sélectionner
from giacpy import simplify
giac("printpow(1)") # trick to force the ^ printing with giac
print simplify("x0^6+2.0*x1^6+(4.0+3.5527136788e-015*i)*x2^6+(-1.0-1.42108547152e-014*i)*x0*x1^5+1.0*x0*x2^5+(-2.0-2.84217094304e-014*i)*x1*x2^5+(4.0-1.7763568394e-015*i)*x0^2*x2^4+(-4.0-7.1054273576e-015*i)*x0^3*x2^3+(1.0+1.42108547152e-014*i)*x0^4*x1^2+(1.0+1.42108547152e-014*i)*x0^4*x2^2-2.0*x0^5*x2+(2.0-2.84217094304e-014*i)*x1^4*x2^2-8.0*x0*x1^2*x2^3-1.0*x0*x1^3*x2^2+(-12.0-7.1054273576e-015*i)*x0*x1^4*x2+(3.0-4.97379915032e-014*i)*x0^2*x1*x2^3+(18.0+3.5527136788e-014*i)*x0^2*x1^2*x2^2+(5.0+3.5527136788e-014*i)*x0^2*x1^3*x2-5.0*x0^3*x1*x2^2-x0^6+2*x0^5*x2-x0^4*x2^2-x0^4*x1^2+4*x0^3*x2^3+5*x0^3*x2^2*x1-4*x0^2*x2^4-3*x0^2*x2^3*x1-18*x0^2*x2^2*x1^2-5*x0^2*x2*x1^3-x0*x2^5+8*x0*x2^3*x1^2+x0*x2^2*x1^3+12*x0*x2*x1^4+x0*x1^5-4*x2^6+2*x2^5*x1-2*x2^2*x1^4-2*x1^6")
In most situations I do only need symbolic computations but there are instances when I can only solve my problem numerically (through some roots of a high degree polynomial) and to assure myself that I have the correct result is important.
Edit: I just want to report that putting the expression in "expand" will work.
Jose