non linear optimization.

    CT_mod= (alpha).*(((tetaT).*den_T.*pi.*(DT.^2).*LT)./4).*c_T;
CH1_mod = ((1-alpha).*(((tetaT).*den_T.*pi.*(DT.^2).*LT)./4).*c_T)+((beta).*((tetaH).*den_H.*(pi./12).*LH.*((DT.^2)+(DC.^2)+(DT.*DC))).*c_H);
CH2_mod = (1-beta-gama).*((tetaH).*den_H.*(pi/12).*LH.*((DT.^2)+(DC.^2)+(DT.*DC))).*c_H;
CH3_mod = ((1-epsi).*((((tetaC).*den_C.*pi.*(DC.^2).*LC)./4).*c_C))+((gama).*((tetaH).*den_H.*(pi/12).*LH.*((DT.^2)+(DC.^2)+(DT.*DC))).*c_H);
CC_mod = (epsi).*((((tetaC).*den_C.*pi.*(DC.^2).*LC)./4).*c_C);

I want to solve above equations for alpha,beta,gama,epsi,tetaT,tetaH,tetaC, remaining CT_mod,CH1_mod,CH2_mod,CH3_mod,CC_mod,DT,DC,LH,LT,LC are known parameter. Above equations are repeated for 8 different objects. so, total around 40 equations. I tried different possible ways to solve, But I couldn't. I want to minimise above equations, i.e minimising RMSE, finding better unknowns. could someone help me to figure it out?

[Chan]

could anyone help me with the solution, please?

Answer 1

[Torsten]

Use "lsqnonlin".

Best wishes

Torsten.

[Chan]

Thank you Torsten for your reply, could you please elaborate your answer because I tried with lsqnonlin also. I'm confused with constrain and unconstrains in the syntax.

[Torsten]

Please post your MATLAB code so far.

Best wishes

Torsten.