Error : Matrix dimensions must agree

 I have written the follwing LMI in matlab 

(A1-B*F1)'  *  P  *  (A1-B*F1)  -  P  <  0

where, A1 is a 12 x 12 matrix B is a 12 x 4 matrix and F1 is a 4 x 12 matrix

A1=[0 0 0 0 0 0 1 0 0 0 0 0;0 0 0 0 0 0 0 1 0 0 0 0;0 0 0 0 0 0 0 0 1 0 0 0;0 0 0 0 0 0 0 0 0 0 0 1;0 0 0 0 0 0 0 0 0 0 1 0;0 0 0 0 0 0 0 0 0 1 0 0;0 0 0 0 -9.4757 2.539 0 0 0 0 0 0;0 0 0 0 2.539 9.4757 0 0 0 0 0 0;0 0 0 0 0 0 0 0 0 0 0 0;0 0 0 0 0 0 0 0 0 0 0 0;0 0 0 0 0 0 0 0 0 0 0 0;0 0 0 0 0 0 0 0 0 0 0 0];
B=[0 0 0 0;0 0 0 0;0 0 0 0;0 0 0 0;0 0 0 0;0 0 0 0;0 0 0 0;0 0 0 0;-1.4286 0 0 0;0 0.24162 0 0;0 0 0.24162 0;0 0 0 0.80541];

setlmis([]);
P=lmivar(1,[12 1]);
F1=lmivar(2,[4 12]);
lmiterm([1 1 1 P],(A1-B*F1)',(A1-B*F1));       
lmiterm([1 1 1 P],1,-1);lmis=getlmis;
[tmin,xfeas]=feasp(lmis);
f1=dec2mat(lmis,xfeas,F1)

but its giving an error '' Matrix dimensions must agree '' can some one help why?

Answer 1

[dpb]

(A1-B*F1)'  *  P  *  (A1-B*F1)  -  P  <  0

where, A1 is a 12 x 12 matrix B is a 12 x 4 matrix and F1 is a 4 x 12 matrix

(A1-B*F1)'  *    P              * (A1-B*F1)
 [12x12]    * [12 1] --> [12x1] *  [12x12]

BOOM! You're trying to multiply a column vector on the left of the square array...

[Ahmad Sheikh]

well

P=lmivar (1,[12 1]) 
it doesnt show that P is a 12x1 matrix.

[dpb]

Oh, yeah? Syntax surely looks like it would be....so what is it?

But whatever, work thru the expression as shown; bound to find somewhere it breaks down -- maybe there's a problem in association/precedence in computer evaluation from what is intended mathematically?