## 105 Reputation

12 years, 91 days

## Add on question to Matrix dot product...

Hi, I have another add on question regarding the dot product of matrix :

with(LinearAlgebra):

A:=Matrix([[3,t,2f],[k,4,w]])   ###2x3 matrix

B:=Matrix([[g],[h],[m]])   ###3x1 matrix

Method 1 : why can I not get "DotProduct(A,B)"?

Method 2: but when I put down "A.B", it gives me the answer.

I try again with C:=Matrix([[a,b]])   ###1x2 matrix

I then put down "B.C" (not possible case) which gives me a wrong answer, hence, I cannot use the second method. Could you let me know how do I make the Method 1 work please?

## Further on question...

Hi, Thank you for your help.

I have now a further question. I only have one matrix : se00:=Matrix([[4,2,-1],[2,16,2],[-1,2,4]])

I want to add them up as above. Here is what I did :

>>num:=16

>>ie0:=Matrix(33)

>>for m from 1 to num-1 do

n1:=m*2+1:

ie0[n1..n1+2,n1..n1+2]:=se00

end do

Problem : it does not give me a 33x33 matrix

Thx

## Further on question...

Hi, Thank you for your help.

I have now a further question. I only have one matrix : se00:=Matrix([[4,2,-1],[2,16,2],[-1,2,4]])

I want to add them up as above. Here is what I did :

>>num:=16

>>ie0:=Matrix(33)

>>for m from 1 to num-1 do

n1:=m*2+1:

ie0[n1..n1+2,n1..n1+2]:=se00

end do

Problem : it does not give me a 33x33 matrix

Thx

## Hi, may I know why everytime I press ent...

Hi, may I know why everytime I press enter, the for loop gives me an increase in multiple of two? for example, first it gives me 58, then if i press enter gain, it gives me 116, and if i press enter again, it gives me 174 and so on...

## Hi, may I know why everytime I press ent...

Hi, may I know why everytime I press enter, the for loop gives me an increase in multiple of two? for example, first it gives me 58, then if i press enter gain, it gives me 116, and if i press enter again, it gives me 174 and so on...

## @Jarekkk  Hi, if I join two 3x3 ma...

Hi, if I join two 3x3 matrix together, I want to get a 5x5 matrix.

## Thank you very much for your help. I nee...

Thank you very much for your help. I needed the first scenario, i left it as an operator because i need to differentiate and integrate it later on.

## Thank you very much for your help. I nee...

Thank you very much for your help. I needed the first scenario, i left it as an operator because i need to differentiate and integrate it later on.

## Hi, I don't really understand your solut...

Hi, I don't really understand your solution, could you please explain what are the "/" and "\" symbols please? Thank you.

## Hi, I don't really understand your solut...

Hi, I don't really understand your solution, could you please explain what are the "/" and "\" symbols please? Thank you.

## Thank you very much. This is really help...

Thank you very much. This is really helpful.

## Thank you very much. This is really help...

Thank you very much. This is really helpful.

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