module_init_utilities.F

1 MODULE module_init_utilities
2 
3 CONTAINS
4 
5  real function interp_0( v_in,  &
6                          z_in, z_out, nz_in  )
7  implicit none
8  integer nz_in, nz_out
9  real    v_in(nz_in), z_in(nz_in)
10  real    z_out
11 
12  integer kp, k, im, ip
13  logical interp, increasing_z 
14  real    height, w1, w2
15  logical debug
16  parameter ( debug = .false. )
17 
18 ! does vertical coordinate increase or decrease with increasing k?
19 ! set offset appropriately
20 
21  height = z_out
22 
23  if(debug) write(6,*) ' height in interp_0 ',height
24 
25  if (z_in(nz_in) .gt. z_in(1)) then
26 
27     if(debug) write(6,*) ' monotonic increase in z in interp_0 '
28     IF (height > z_in(nz_in)) then
29       if(debug) write(6,*) ' point 1 in interp_0 '
30       w2 = (z_in(nz_in)-height)/(z_in(nz_in)-z_in(nz_in-1))
31       w1 = 1.-w2
32       interp_0 = w1*v_in(nz_in) + w2*v_in(nz_in-1)
33     ELSE IF (height < z_in(1)) then
34       if(debug) write(6,*) ' point 2 in interp_0 '
35       w2 = (z_in(2)-height)/(z_in(2)-z_in(1))
36       w1 = 1.-w2
37       interp_0 = w1*v_in(2) + w2*v_in(1)
38     ELSE
39       if(debug) write(6,*) ' point 3 in interp_0 '
40       interp = .false.
41       kp = nz_in
42       DO WHILE ( (interp .eqv. .false.) .and. (kp .ge. 2) )
43         IF(   ((z_in(kp)   .ge. height) .and.     &
44                (z_in(kp-1) .le. height))        )   THEN
45           w2 = (height-z_in(kp))/(z_in(kp-1)-z_in(kp))
46           w1 = 1.-w2
47           interp_0 = w1*v_in(kp) + w2*v_in(kp-1)
48           if(debug) write(6,*) ' interp data, kp, w1, w2 ',kp, w1, w2
49           if(debug) write(6,*) ' interp data, v_in(kp), v_in(kp-1), interp_0 ', &
50                      v_in(kp), v_in(kp-1), interp_0
51           interp = .true.
52         END IF
53         kp = kp-1
54       ENDDO
55     ENDIF
56 
57  else
58 
59     if(debug) write(6,*) ' monotonic decrease in z in interp_0 '
60 
61     IF (height < z_in(nz_in)) then
62       if(debug) write(6,*) ' point 1 in interp_0 '
63       w2 = (z_in(nz_in)-height)/(z_in(nz_in)-z_in(nz_in-1))
64       w1 = 1.-w2
65       interp_0 = w1*v_in(nz_in) + w2*v_in(nz_in-1)
66     ELSE IF (height > z_in(1)) then
67       if(debug) write(6,*) ' point 2 in interp_0 '
68       w2 = (z_in(2)-height)/(z_in(2)-z_in(1))
69       w1 = 1.-w2
70       interp_0 = w1*v_in(2) + w2*v_in(1)
71     ELSE
72       if(debug) write(6,*) ' point 3 in interp_0 '
73       interp = .false.
74       kp = nz_in
75       height = z_out
76       DO WHILE ( (interp .eqv. .false.) .and. (kp .ge. 2) )
77         IF(   ((z_in(kp)   .le. height) .and.     &
78                (z_in(kp-1) .ge. height))             )   THEN
79           w2 = (height-z_in(kp))/(z_in(kp-1)-z_in(kp))
80           w1 = 1.-w2
81           interp_0 = w1*v_in(kp) + w2*v_in(kp-1)
82           interp = .true.
83         END IF
84         kp = kp-1
85       ENDDO
86     ENDIF
87 
88  end if
89 
90  return
91  END FUNCTION interp_0
92 
93 END MODULE module_init_utilities
94 
95