Hello everyone, Hello everyone, I have a function in the first row of a result matrix, and also in the second.
I'm separating the first row to write only the parts of it into a new matrix, for example, a multiplication by the second derivative of phi1. [image: pic_result matrix.jpg] Unfortunately, there's no result, just square brackets. Can anyone help? Thanks in advance. *Sympy Code:* #Testmatrix C = d*sp.diff(phi1(t), t)+l*m*(2*g*sp.sin(phi1(t))+l*sp.sin(phi1(t)-phi2(t))*(sp.diff(phi2(t), t))**2+ l*sp.cos(phi1(t)-phi2(t))*sp.diff(phi2(t), t,t)+ 2*l*sp.diff(phi1(t), t,t)) D = sp.diff(phi2(t), t) + sp.diff(phi1(t), t) Bw_Lag_Q_Test = sp.Matrix([[C], [D]]) Bw_Lag_Q_Test erste_reihe_BW_Test = Bw_Lag_Q_Test.row(0) erste_reihe_BW_Test # Extract parts of erste_reihe_BW_Test erste_reihe_BW_Test = Bw_Lag_Q_Test.row(0) Extract_0 = [term.coeff(sp.diff(phi1(t), t,t)) for term in erste_reihe_BW if term.has(sp.diff(phi1(t), t,t))] Extract_0 [image: pic_empty square bracket.jpg] -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/sympy/53ab1baa-d5ad-4c03-b02d-6a55b8358ba0n%40googlegroups.com.
