How do I solve this problem? I want to make code to solve this problem. I made the matrix D using triu function in matlab and than D=t+t.'

I have one vector and one matrix..

Facility_units=[4 2 3 1]

total=4+2+3+1=10

matrix D=

[0 4 2 4 ;

4 0 1 3 ;

2 1 0 2 ;

4 3 2 0]

D is symmetric matrix in which diagonal element is 0 and upper triangle is similar to lower triangle.

I want the output in this form e.g.

output= 10*10 matrix i.e. total*total

[

0 0 0 0 4 4 2 2 2 4 ;

0 0 0 0 4 4 2 2 2 4 ;

0 0 0 0 4 4 2 2 2 4 ;

0 0 0 0 4 4 2 2 2 4 ;

4 4 4 4 0 0 1 1 1 3 ;

4 4 4 4 0 0 1 1 1 3 ;

2 2 2 2 1 1 0 0 0 2 ;

2 2 2 2 1 1 0 0 0 2 ;

2 2 2 2 1 1 0 0 0 2 ;

4 4 4 4 3 3 2 2 2 0 ]

output matrix is 10-by-10 in which elements are repeated according to vector Facility_units.

1st facility having 4 units, 2nd has 2 units, 3rd has 3 units and 4th has 1 unit.

D is the matrix shows the distance between each facility. e.g. distance between facility 1 and 2 is 4,

between 1 and 3 is 2 and between 1 and 4 is 4. according to that matrix D (i.e. distance matrix) is made.

Now i want the output that shows the distance between each unit of the facility with any other units.

e.g. units of same facility having distance 0. 1st facility have 4 units that is why in output matrix 1:4 row

by 1:4 column is 0.

than distance of units of facility 2 with facility 1 is 2.

Answer 1

[Roger Stafford]

'Facility_units' must be a row vector of non-negative integers in the following:

   c = cumsum(Facility_units);
   ix = cumsum(accumarray([1,c(1:end-1)+1].',1,[c(end)+1,1]));
   output = D(ix(1:end-1),ix(1:end-1));

[Shweta gupta]

Thanks a lot sir. :) thanks for your help. you solved my problem in 3 lines of code.