Making a transformation matrix in matrix format

Hi, I've a matrix shows below

syms th d alph l
A =  [cos(th)  -cos(alph)*sin(th)  sin(alph)*sin(th)  l*cos(th);
    sin(th)  cos(alph)*cos(th) -sin(alph)*cos(th)  l*sin(th);
    0 sin(alph) cos(alph) d;
    0 0 0 1]

i end up getting 4 matrices

A =
[cos(th), -cos(alph)*sin(th),  sin(alph)*sin(th), l*cos(th)]
[sin(th),  cos(alph)*cos(th), -sin(alph)*cos(th), l*sin(th)]
[      0,          sin(alph),          cos(alph),         d]
[      0,                  0,                  0,         1]

but I want it in one matrix format, what can I do with it?

[C K Chan]

 syms th d alph l
 A =  [ cos(th)  -cos(alph)*sin(th)  sin(alph)*sin(th)   l*cos(th);
        sin(th)  cos(alph)*cos(th)   -sin(alph)*cos(th)  l*sin(th);
           0 sin(alph)	cos(alph)	d;
           0	0	0	1 ];

syms th1
A1 = subs(A,{l,alph,d,th},{0,pi/2,20,th1})

or I use subs numbers in the the matrix, I end uo getting this 4 matrices

A1 =
[cos(th1), 0,  sin(th1),  0]
[sin(th1), 0, -cos(th1),  0]
[       0, 1,         0, 20]
[       0, 0,         0,  1]

I want to get it in one matrix like below

A1 =
cos(th1), 0,  sin(th1),  0;
sin(th1), 0, -cos(th1),  0;
       0, 1,         0, 20;
       0, 0,         0,  1;

Thank you!

Answer 1

[Paul]

You're not getting 4, 1 x 4 matrices. It just looks like that because of the formatting to the diplay.

>> syms th d alph l
 A =  [ cos(th)  -cos(alph)*sin(th)  sin(alph)*sin(th)   l*cos(th);
        sin(th)  cos(alph)*cos(th)   -sin(alph)*cos(th)  l*sin(th);
           0 sin(alph)	cos(alph)	d;
           0	0	0	1 ];
>> size(A)

ans =

     4     4

As shown, A is, in fact, one 4 x 4 sym matrix.

[C K Chan]

Thank you for your reply.

I want to get one 4x4 matrix. (like below)

 A =     cos(th)  -cos(alph)*sin(th)  sin(alph)*sin(th)   l*cos(th)
         sin(th)  cos(alph)*cos(th)   -sin(alph)*cos(th)  l*sin(th)
         0 sin(alph)	cos(alph)	d
         0	0	0	1 

but in fact, I getting four 1x4 matrices.

A =
 
[cos(th), -cos(alph)*sin(th),  sin(alph)*sin(th), l*cos(th)]
[sin(th),  cos(alph)*cos(th), -sin(alph)*cos(th), l*sin(th)]
[      0,          sin(alph),          cos(alph),         d]
[      0,                  0,                  0,         1]

[Paul]

As I showed, A is a 4x4 matrix. What do you get for

>> size(A)

[C K Chan]

I get 4x4 for A.

[Paul]

So everything works as you need it to work?

[C K Chan]

Thanks a lot.

I fixed it.