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matrix multiplication

3 messages · flokke, Brad Patrick Schneid, Rolf Turner

flokke
# 
Dear all, 
Sorry to bother you with such a stupid question, but I just cannot find the
solution to my problem.

I'd like to use matrix multiplication for meanA and factorial 3. 
I use the command meanA%*%factorial 3. 
But everything I get is: Error in factorial3 %*% A : non-conformable
arguments

I know that the number of the columns of the first vector has to be the same
number of rows of the 
second vector to be able to use matrix multiplication, but that is the case
here. I also tried it with 
two columns for factorial 3 and that didnt work either. 

Can someone help me out with this?'

these are my matrices:

meanA
         [,1]     [,2]
[1,] 3.666667 4.666667
[,1]
[1,]    1

Thank you so much!
Cheers, maria

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Brad Patrick Schneid
# 
Your question as answered by Timothy in your previous thread 

http://r.789695.n4.nabble.com/Re-Creating-the-mean-using-algebra-matrix-td3895689.html
flokke wrote:
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Rolf Turner
#
On 12/10/11 09:11, flokke wrote:
first ***MATRIX***
second ***MATRIX***
No it isn't!!!  Your ``factorial3'' has ***one*** row, and
     ``meanA'' has ***two*** columns.  So the arrays are
     not conformable, just like the error message says!

     There are three sorts of people; those who can count,
     and those who can't!
Try it with two ***rows*** for factorial3!!!

     And watch those spaces in names.  They don't belong.
To repeat:  (1 x 2) times (1 x 1) doesn't work.
Note that (n x 2) times (2 x m) *does* work, and gives an (n x m) result.

     cheers,

         Rolf Turner