Multiplication between 2 matrix

Asked by Danilo Teran on 6 Nov 2017

Latest activity Edited by Danilo Teran on 6 Nov 2017

1 view (last 30 days)

Hi, I need to multiply one matrix, which only number has A = [1 0; 2 3] with a matrix(array) with variables, which are not define yet, but they are numbers, which are not yet defined B = [a b; c d]

I need to get one general solution in order to change a,b,c,d values

Thanks in advance

0 Comments

2 Answers

Link

Answer by Mischa Kim on 6 Nov 2017

Edited by Mischa Kim on 6 Nov 2017

Accepted Answer

Danilo, use the Symbolic Math Toolbox

 syms B C a b c d
 A = [1 0; 2 3];
 B = [a b; c d];
 C = A*B
 C =
 [         a,         b]
 [ 2*a + 3*c, 2*b + 3*d]

1 Comment

Danilo Teran on 6 Nov 2017

Hi Mischa,

I get it, but as you can see there ist not a mtrix there. In my example I need to do this syms S1 A1 S2 A2 K2 A B C Ss K12 TR AR BR CRT TER1 e BN AII BI CIT A=[-K12/A1 K12/A1 ; K12/A2 -(K12+K2)/A2] B=[S1/A1 0; 0 S2/A2] C=[1 0; 0 K2]

Ss=[B A*B]

STR=[0 1]*inv(Ss)

TR=inv([STR;STR*A])

% TR1=inv([STR;STR*A])

AR=inv(TR)*A*TR

BR=inv(TR)*B

CRT=C*TR

TRE1=[C C*inv(A);STR STR*A]

TE=inv(TRE1)

AE=TRE1*A*TE

BE=TRE1*B

CET=C*TE

zer=tzero(A,B,C,0);

e=C*A*TE

BN=[0 1/CRT(2)]

AII=AE(1,1)

BI=[0 CRT(2)]

CIT=[1 0]

CTN=(1/BN(2))*e

ANN=AE(2,2)

My number values will be S1 S2 A1 A2 K12

But I am getting a problem

Error in Matrixconletras (line 9) STR=[0 1]*inv(Ss)

Link

Answer by Jan on 6 Nov 2017

Or perhaps:

 C = [a,         b; ...
      2*a + 3*c, 2*b + 3*d];

You are now following this question

Danilo Teran (view profile)