11 6
6. Spatial Fisheries Model
Ei[Regi on_2] = Di [Re g ion_2 ]* E
Ei[Regi on_3] = Di[Region_3] *E
Ei[Region_4 ] = Di [Region_4] *E
J = . 22
Ki[ Re g i on ] = 2 0 0 0 0
Mi[Region] = °
N = ARRAYSUM(Ni [ *])
N_DOT = ARRAYSUM(Ni_DOT[ *])
N_minus_N4 = N-Ni[Region_4]
P = 2. 9
RAND[P12] = RANDOM(O ,l ,l)
RAND[P13]
RANDOM(0 ,1, 2)
RAND[P14] = RANDOM(0,1 ,3)
RAND[P21] = RANDOM(0,1,4)
RAND[P23] = RANDOM(0,1,5)
RAND [P 24] = RANDOM(O, 1,6)
RAND[P31] = RANDOM(0,1 ,7)
RAND [P32] = RANDOM(0 ,1 , 8)
RAND [P34] = RANDOM(0,1,9)
RAND [P41] = RANDOM(O, 1,10)
RAND [P4 2] = RANDOM (O,l ,ll)
RAND[P43] = RANDOM(0, 1 , 1 2)
RAND_N1
RAND [P 1 2]+RAND[P13]+RAND[P14]
RAND_ N2
RAND[P21] +RAND[P23]+RAND[P24]
RAND_N3
RAND [P 31 ]+RAND[P3 2]+RAND[P34]
RAND_N4 = RAND[ P41] +RAND[ P42 ] +RAND[ P4 3]
Ri [Regi on] = . 6
TOTAL_M = ARRAYSUM( M[*])
V = .00006
6.4. Development of a User Interface
At times, you may find yourself wishing to have others use your model
without their having to understand all of STELLA's graphical features used
to pro gram the model. If so, you may want to add a user interface that
makes it easy for others to choose their own initial conditions and parameter values without having to directly manipulate the stocks and converters.
Click on the upward-p ointing triangle at the upper left-hand come r of
the scree n (Figure 6.17). This gets you to another layer of your STELLA
model-one that is designed to create a user interface. Notice along the top
of the screen the appea rance of many of the symbo ls, such as those for