how to do matrix symbolic differentiation
1 view (last 30 days)
Show older comments
so I wrote this to calucalte Om2 and OmA, using symbolic differentiation but I get an error saying
"Warning: Unable to find explicit solution.
> In solve (line 317)
In Gr_51_Aamna (line 72)
Error using solve>getEqns (line 404)
Input argument contains an empty equation or variable."
note that i already got Th2_2 and ThA_2 in separate matrices
Thanx in advance for any help..
% Parameters:
L1=1.8;
L3=2.4;
L2=2.2;
L4=2.7;
L1_2=1.18;
L2_2=0.467;
Th1= 134;
Th1_2=142.5;
v=0.0362;
for t=0:10
LA(:,t+1) = 1.15-(v*t);
end
%Parameters
syms L1 L2 L3 L4 L1_2 L2_2 Th1 Th1_2 integer
% variables and their derivatives
syms LA Th2_2 Om2 Al2 Th3_1 Om3 Al3 Th4_1 Om4 Al4 ThA_2 OmA AlA integer
%loop eqn.
L_eqn1 = L2_2*exp(1i*Th2_2)+LA*exp(1i*ThA_2) -L1_2*exp(1i*Th1_2)==0;
L_eqn2 = L2*exp(1i*Th2_2)-L3*exp(1i*Th3_1)+L4*exp(1i*Th4_1) -L1*exp(1i*Th1)==0;
%velocity eqn for Om2 and OmA.
dL_eqn1 = diff(L_eqn1,Th2_2)*Om2 +diff(L_eqn1,ThA_2)*OmA+ v*t;
real_vel_eqn1 = real(dL_eqn1);
imag_vel_eqn1 = imag(dL_eqn1);
[Om2, OmA]=solve (real_vel_eqn1, imag_vel_eqn1);
1 Comment
Harsha Priya Daggubati
on 6 Nov 2019
Hi,
I doubt you are giving wrong syntax to 'solve'. solve expects it's first argument to be an equation, which in your case is real part of the equation. I guess it is causing the error to popup. Refer to the following link for help:
Hope this helps!
Answers (0)
See Also
Categories
Find more on Assumptions in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!