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Blockmat(2,3, {A,B,C,D,E,F})--> [A B C; D E F]
Blockmat(3,2, {A,B,C,D,E,F})--> [A B; C D; E F]
Blockmat(1,6, {A,B,C,D,E,F})--> [A B C D E F]
A, B, C, D, E, F are matrices of equal dimensions.

Code:

#cas

Blockmat(n,p,lst):=

BEGIN

local j,k,c,d,m3,m2;

IF ((n*p)<>size(lst)) THEN RETURN("matrices sizes"); END

m2:=[]; m3:=[]; L0:={};

if p==1 then Blockmat1();return(m2); end;

for k from 1 to n do

IF k==1 THEN 

for j from 1 to p do

L0(j):=lst(j);

end;

m2:=trn(concat(L0));

c:=p; 

ELSE

L0:={};

d:=1;

for j from c+1 to k*p do

L0(d):=lst(j);

d:=d+1;

end;

c:=k*p;

m3:=trn(concat(L0));

m2:=concat(m2,m3);

END;

end;

return(trn(m2));

END;

#end

#cas

Blockmat1()

BEGIN

LOCAL j;

L0:={};

B:=0;

[A,B]:=DIM(lst(1));

for j from 1 to (size(lst)-1) do

IF (DIM((lst(j)))<>DIM((lst(j+1)))) THEN kill; END;

end;

for j from 1 to (size(lst)) do

L0:=concat(L0,mat2list(lst(j)));

end;

IF B==0 THEN m2:=(list2mat(L0,colDim(lst(1)))); ELSE m2:=(list2mat(L0,B)); END;

END;

#end

Isn't there already a command that does this (list2mat)?

if matrix A= [1 2; 3 4] and B =[5 6; 7 8]
to block A and B into 2*1 is C=[A;B]=[1 2; 3 4;5 6;7 8]
list2mat will block it to C=[[A],[B]]=[[1 2; 3 4];[5 6; 7 8]] with extra brackets

if you have matrices A,B,C,D to be block into 2*2 matrix
A,B need to augmented, C ,D need to augmented---> CONCAT in hp prime
then the first has to stack on the later---> no STACK in hp prime;
that's what my code does...

I see now; this little program is quite useful.

toshk

Han

toshk

Han