====== Varga's transformation ====== Subject: Re: [SOCNET] need for a procedure From: "varga attila" Date: Fri, August 28, 2009 09:54 To: vladimir.batagelj@fmf.uni-lj.si Dear Vladimir Batagelj! I hope this expression will be understendable! node "i" and "j" have values "m" and "n", edge "ij" has value "k" I wan't to compute these quantities. These have to be valued lines i.e. valued arcs: k/m=ij k/n=ji Varga Attila Thanks to Andrej who added to Pajek operations Net/Transform/Remove/Triangle it is now possible to make this transformation in Pajek. 
output   operation
Ndir   : Net/Transform/Edges -> Arcs [Yes]
U      : Net/Transform/Remove/Triangle/Lower [Yes]
       : select Ndir
L      : Net/Transform/Remove/Triangle/Upper [No]
q=1/p  : Vector/Transform/Invert
       : select U
q#U    : Operations/Vector/Vector#Network/Output
       : select L
q#L    : Operations/Vector/Vector#Network/Input
       : select q#U as second network
U+L    : Nets/Union of lines
       : Net/Transform/Remove/Multiple Lines/Min Value [No]
       : dispose auxiliary data
This sequence of commands is stored also in the macro **''Varga.mcr''** and you can make the transformation simply by selecting the network and vector and then running the macro {{:dl:varga.zip}} Macro/Play [Varga.mcr] **input :** Valued network w[i,j], vector p[i] with nonzero values\\ **output:** Directed network v[i,j] with values v[i,j] = w[i,j]/p[i], i 
        w     1  2  3  4      p
------------------------     ---
 v1     1.    6  0  5 10      2
 v2     2.    0  0  1  4      3
 v3     3.    5  1  3  8      1
 v4     4.   10  4  8  0      4

we get
        v       1    2    3    4
--------------------------------
 v1     1.   3.00 0.00 2.50 5.00
 v2     2.   0.00 0.00 0.33 1.33
 v3     3.   2.50 0.33 3.00 8.00
 v4     4.   5.00 1.33 8.00 0.00
The macro **''varga''** was prepared by Vladimir Batagelj on 6. September 2009.