why do I get error for Undefining function sdpvar and how can I solve it?
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I got an error saying:
Undefined function 'sdpvar' for input arguments of type 'double'.
Error in Untitled3 (line 1)
A=sdpvar(3,1); Tc=sdpvar(2,1); Tout=sdpvar(3,1); gam=1e5;
for the following code:
4 个评论
Geoff Hayes
2022-4-12
@Meme alcute - what is returned when you try
which -all sdpvar
from the command line? Please copy and paste the results to this question.
KSSV
2022-4-12
spdvar is not an inbuilt function. It is user defined function. We cannot help you unless the function is attached here.
Meme alcute
2022-4-12
Here is the problem 
And here is the answer I got from Solving Optimization Problems with MATLAB book. However, when I use exactly the same code I get an error as stated above.
And here is the answer I got from Solving Optimization Problems with MATLAB book. However, when I use exactly the same code I get an error as stated above. 
Meme alcute
2022-4-12
This is the code:
A=sdpvar(3,1); Tc=sdpvar(2,1); Tout=sdpvar(3,1); gam=1e5;
U=[120,80,40]; Tcin=100; T1in=300; T2in=400;
T3in=600; Tcout=500;
cons=[Tc(1)+Tout(1)-Tcin-T1in<=0,
-Tc(1)+Tc(2)+Tout(2)-T1in<=0,
Tout(3)-Tc(2)-T3in+Tcout<=0,
A(1)-A(1)*Tout(1)+gam*Tc(1)/U(1)-gam*Tcin/U(1)<=0,
A(2)*Tc(1)-A(2)*Tout(2)-gam*Tc(1)/U(2)+gam*Tc(2)/U(2)<=0,
A(3)*Tc(2)-A(3)*Tout(3)-gam*Tc(2)/U(3)+gam*Tcout/U(3)<=0,
100<=A(1)<=10000, 1000<=A([2,3])<=10000,
10<=Tc<=1000, 10<=Tout<=1000];
opt=sum(A);
optimize(cons,opt), value(A), value(Tc), value(Tout)
and here is the error:
回答（1 个）
Cris LaPierre
2022-4-12
0 个投票
This is not a MathWorks supplied toolbox, so you will need to follow the intructions given to you to install and use this toolbox.
5 个评论
Meme alcute
2022-4-12
Cris LaPierre
2022-4-12
Not sure, as it's not a MathWorks product, but I think exploring the Download menu on the page I linked to would be a good place to start.
Steven Lord
2022-4-12
Click the Download link on the page to which Cris linked and follow the instructions on that page.
Meme alcute
2022-4-12
Muhammad Yasir
2023-1-11
It is keyword/function of YALMIP. It's not a standard MATLAB operator or keyword.
Have you set path to YALMIP forlder from MATLAB?
Seems like your MATLAB is not recognizing YALMIP supported functions.
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