Dot product of a column vector by its own elements

Hi, I have a matrix containing coordinates(x,y,z) and I am trying to find the dot product of the elements inside the vector. The matrix looks like this:

 %    a(x)     a(y)      a(z)        
   -0.0022   -0.0131    0.9999
 %    b(x)     b(y)      b(z)
   -0.8062    0.2794    0.5216
 %    c(x)     c(y)      c(z)
   -0.9325    0.0547   -0.3570

I want to achieve a dot product matrix of something like this:

   a.a    a.b    a.c
   b.a    b.b    b.c
   c.a    c.b    c.c

I tried writing a code

 Dot_P(1,1)= dot(matrix(1,:),matrix(1,:));
 Dot_P(1,2)= dot(matrix(1,:),matrix(2,:));
 Dot_P(1,3)= dot(matrix(1,:),matrix(3,:));

but this is hard coding and is not efficient, any help is appreciated!

[Jan]

The question is not clear. You want to achieve a matrix, but post a hard coded version to create a vector.

Please post the inputs such that they can be used by copy&paste to suggest a solution. This is more convenient for the ones who want to help you.

[Goh Jia Man]

Sorry for the confusion, let's say I have a [m x 1] matrix, I want to create a new symmetric square matrix, which has the form of

 m1.m1    m1.m2    m1.m3 
 m2.m1    m2.m2    m2.m3
 m3.m1    m3.m2    m3.m3

Answer 1

[Jan]

With some guessing:

X = [-0.0022, -0.0131,  0.9999; ...
     -0.8062,  0.2794,  0.5216; ...
     -0.9325,  0.0547, -0.3570];
P = X * X.'

Now your "c" is X(1, :). Then e.g. P(3,3) equals c * c'.

[Goh Jia Man]

Oh thank you so much! I was cracking my head as to how do I use the dot(A,B) function to achieve the matrix

Answer 2

[Fangjun Jiang]

a=[-0.0022   -0.0131    0.9999];
b=[-0.8062    0.2794    0.5216];
c=[-0.9325    0.0547   -0.3570];

M=[a;b;c]
M*M'

[Goh Jia Man]

Thank you for the response!