https://github.com/cran/fields
Tip revision: 5c24a1f871f2c5d4b6da602c080c2b28df583875 authored by Douglas Nychka on 16 December 2016, 10:13:26 UTC
version 8.8
version 8.8
Tip revision: 5c24a1f
radbas.f
c fields, Tools for spatial data
c Copyright 2015, Institute for Mathematics Applied Geosciences
c University Corporation for Atmospheric Research
c Licensed under the GPL -- www.gpl.org/licenses/gpl.html
c**** subroutine to fill in the omega ( or K) matrix for
c**** ridge regression S funcion
c**** K_ij= radfun( distance( x1_i, x2_j))
c
subroutine radbas( nd,x1,n1, x2,n2, par, k)
integer nd,n1,n2,ic
double precision par(2), x1(n1,nd), x2(n2,nd), k(n1,n2)
double precision xtemp, radfun
c **** loop through columns of output matrix K
c*** outer most loop over columns of x1 and x2 should reduce memory swaps
do ic= 1, nd
do j =1,n2
xtemp= x2(j,ic)
do i= 1, n1
c** accumulate squared differences
k(i,j)= (x1(i,ic)- xtemp)**2 + k(i,j)
enddo
enddo
enddo
c**** at this point k( i,j) is the squared distance between x1_i and x2_j
c*** now evaluate radial basis functions
do j =1,n2
do i= 1, n1
k(i,j)= radfun( k(i,j), par(1), par(2) )
enddo
enddo
return
end