czsum {orloca} | R Documentation |
The objective function and the gradient function for the min-sum location problem.
czsum(o, cluster, x=0, y=0) czsumgra(o, cluster, x=0, y=0)
o |
An object of loca.p class. |
cluster |
An snow cluster object. |
x |
The x coordinate of the point to be evaluated. |
y |
The y coordinate of the point to be evaluated. |
czsum
returns the objective function of the mini-sum location
problem, sum_{a_i in o} w_i d(a_i, (x,y)), where d(a_i, (x,y)) gives the
euclidean distances between a_i and (x,y).
czsumgra
returns the gradient vector of the function zsum
.
The computations are made at the given cluster.
See http://www.stat.uiowa.edu/~luke/R/cluster/cluster.html for information about computers clusters.
See also zsum
, zsumgra
and zsummin