jspice3 optimization routine: merit
.control
#
# Determines if a given set of margins is better than previous sets.
# Decision is based on marg[0] = minimum normalized margin,
# marg[1] = margin width - to + of minimum margin and
# marg[2] = sum of all margins.  First check marg[0], if it is
# unchanged check marg[1] and marg[2].  Output is in vector
# better, 1 if yes, 0 if no.

# External vectors:
#   upper[], lower[], flags[], margbest[], better
#
# External system vectors:
#   value[]
#
# Internal vectors:
#   me_i, me_marg[], me_u, me_l, me_x 

let me_marg[2] = 0.0
let me_marg[0] = 1.0

let me_i = 0
while (me_i < 20)
    if (flags[me_i] = 0)
        let me_i = me_i + 1
        continue
    endif
    let me_u = abs((upper[me_i] - value[me_i]) / value[me_i])
    let me_l = abs((lower[me_i] - value[me_i]) / value[me_i])
    if (me_u > me_l)
        let me_x = me_l
    else
        let me_x = me_u
    endif
    if (me_x <= me_marg[0])
        let me_marg[0] = me_x
        let me_marg[1] = me_u + me_l
    endif
    let me_marg[2] = me_marg[2] + me_u + me_l
    let me_i = me_i + 1
end

# Determine if trial variable set is better.

better = 0
if ((me_marg[0] > margbest[0]) or \
    (me_marg[0] = margbest[0] and me_marg[1] > margbest[1]) or \
    (me_marg[0] = margbest[0] and me_marg[2] > margbest[2]))

    let better = 1
    let margbest[0] = me_marg[0]
    let margbest[1] = me_marg[1]
    let margbest[2] = me_marg[2]
endif

unlet me_marg me_i me_l me_u me_x
.endc