Use slatec routines (dpchim and dpchfe) to interpolate calculated spectrum to experimental irregular grid of x-values

Snippet from ChatGPT: program pchip_demo implicit none integer, parameter :: dp = kind(1.0d0) integer :: n, m, incfd, i real(dp), allocatable :: x(:), y(:), d(:), goalx(:), goaly(:)

n = 5 allocate(x(n), y(n), d(n)) x = [0.0_dp,1.0_dp,2.0_dp,3.0_dp,4.0_dp] y = [0.0_dp,1.0_dp,0.8_dp,2.5_dp,3.0_dp] incfd = 1

call dpchim(n,x,y,d,incfd)

m = 20 allocate(goalx(m), goaly(m)) do i=1,m goalx(i) = (i-1)*(4.0_dp/(m-1)) end do

call dpchfe(n,x,y,d,incfd,m,goalx,goaly)

do i=1,m print '(F6.3, 2X, F6.3)', goalx(i), goaly(i) end do end program pchip_demo

gfortran pchip_demo.f95 -L/opt/local/lib -lslatec -o pchip_demo