Set_up: Set up
In pwinskill/EPICYST: Cysticercosis ODE and Intervention model

Caculates internal parameters and equilbirum staring values for state variables

Set_up(LEP = 1, delta = 960000, HPS = 10000, PPS = 2000, TPrev = 0.02,
  CPrev = 0.07, PCPrev = 0.2, AEL = 2, ATL = 2, ADI = 3, LEH = 54,
  phi = 0.8, chi = 0.5, RR_cysticercosis = 1, epsilon = 0.01,
  RR_infection = 1, RR_consumption = -0.25)

`LEP`	Pig life expectancy (years)
`delta`	Egg production rate (per month)
`HPS`	Human population size
`PPS`	Pig population size
`TPrev`	Taeniasis prevalence
`CPrev`	Cysticercosis prevalence in humans
`PCPrev`	Cysticercosis prevalence in pigs
`AEL`	Average life expectancy of egg in the environment (weeks)
`ATL`	Average life expectancy of T. solium adult worm in human (years)
`ADI`	Average duration of cycticercosis infection in humans (years)
`LEH`	Average life expectancy of a human (years)
`phi`	Proportion of infected pigs with low-intensity cyst burden
`chi`	Average number of pork meals (200g portion) per person per month
`RR_cysticercosis`	Risk multiplier for Cysticercosis if human has Taeniasis
`epsilon`	Pig rate of loss of naturally aquired immunity
`RR_infection`	Increased RR of infection given consumption of high cyct burden pork, compared with low cyst burden
`RR_consumption`	Decreased RR of consumption of high cyst burden pork, compared with low cyst burden pork