trunk/dyn3d/conf_dat2d.f

module conf_dat2d_m

  ! From conf_dat2d.F, version 1.2 2006/01/27 15:14:22

  IMPLICIT NONE

contains

  SUBROUTINE conf_dat2d(xd, yd, xf, yf, champd, interbar)

    ! Auteur : P. Le Van

    ! Ce sous-programme configure le champ de données 2D 'champd' et
    ! les longitudes et latitudes de telle façon qu'on ait - pi à pi
    ! en longitude et pi/2 à - pi/2 en latitude.
    
    ! This procedure receives a 2D field, with the corresponding
    ! coordinate variables: longitude and latitude.
    ! The procedure converts longitude and latitude to radians, if the
    ! input values are in degrees.
    ! If the input longitudes are between 0 and 2 pi, the procedure
    ! computes the congruent longitudes between -pi and pi, and permutes
    ! them so they stay in increasing order.
    ! If the input latitudes are from south pole to north pole, the
    ! procedure permutes them so they become from north to south.
    ! Any change on longitudes or latitudes induces a change on the 2D field.
    ! If required, the longitudes and latitudes are finally replaced
    ! by their mid-values.

    use nr_util, only: assert_eq, pi

    REAL, intent(in):: xd(:)
    ! (longitudes, in degrees or radians, in increasing order, from 0°
    ! to 360° or -180° to 180°)

    REAL, intent(in):: yd(:)
    ! (latitudes, in degrees or radians, in increasing or decreasing
    ! order, from pole to pole)

    LOGICAL, intent(in), optional:: interbar
    REAL, intent(out):: xf(:), yf(:) ! longitudes and latitudes, in rad
    REAL, intent(inout):: champd(:, :)

    ! Variables locales:

    INTEGER  lons, lats
    LOGICAL radianlon ! "xd" is in degrees
    logical invlon ! "xd" contains longitudes between 0 and 2 pi
    logical radianlat ! "yd" is in rad
    REAL rlatmin, rlatmax, old_xf_1
    INTEGER i, j
    logical mid_values

    !------------------------------

    lons = assert_eq(size(xd), size(xf), size(champd, 1), "conf_dat2d lons")
    lats = assert_eq(size(yd), size(yf), size(champd, 2), "conf_dat2d lats")

    IF (xd(1) >= - pi -0.5 .AND. xd(lons) <= pi + 0.5) THEN
       radianlon = .TRUE.
       invlon    = .FALSE.
    ELSE IF (xd(1) >= -0.5 .AND. xd(lons) <= 2 * pi+0.5) THEN
       radianlon = .TRUE.
       invlon    = .TRUE.
    ELSE IF (xd(1) >= -180.5 .AND. xd(lons) <= 180.5) THEN
       radianlon = .FALSE.
       invlon    = .FALSE.
    ELSE IF (xd(1) >= -0.5 .AND. xd(lons) <= 360.5) THEN
       radianlon = .FALSE.
       invlon    = .TRUE.
    ELSE
       stop '"conf_dat2d": problem with longitudes'
    ENDIF

    rlatmin = MIN(yd(1), yd(lats))
    rlatmax = MAX(yd(1), yd(lats))

    IF (rlatmin >= -pi / 2 - 0.5 .AND. rlatmax <= pi / 2 + 0.5)THEN
       radianlat = .TRUE.
    ELSE IF (rlatmin >= -90. - 0.5 .AND. rlatmax <= 90. + 0.5) THEN
       radianlat = .FALSE.
    ELSE
       stop '"conf_dat2d": problem with latitudes'
    ENDIF

    IF (radianlon)  THEN
       xf(:) = xd(:)
    else
       xf(:) = xd(:) * pi / 180. ! convert to rad
    ENDIF

    IF (radianlat)  THEN
       yf(:) = yd(:)
    else
       yf(:) = yd(:) * pi / 180. ! convert to rad
    ENDIF

    IF (invlon) THEN
       ! On tourne les longitudes pour avoir - pi à + pi :

       ! Get the index of the first longitude > pi:
       i = 1
       do while (xf(i) <= pi)
          i = i + 1
       end do

       xf(i:) = xf(i:) - 2 * pi
       xf(:) = cshift(xf, shift=i - 1)
       champd(:, :) = cshift(champd, shift=i - 1)
    ENDIF

    IF (yd(1) < yd(lats)) THEN
       ! "yd" contains latitudes from south pole to north pole,
       ! reverse their order in "yf":
       yf(lats:1:-1) = yf(:)
       champd(:, lats:1:-1) = champd(:, :)
    ENDIF

    if (present(interbar)) then
       mid_values = interbar
    else
       mid_values = .true. ! default
    end if
    if (mid_values) then
       ! Replace longitudes and latitudes by their mid-values:
       old_xf_1 = xf(1)
       forall (i = 1: lons - 1) xf(i) = 0.5 * (xf(i) + xf(i+1))
       xf(lons) = 0.5 * (xf(lons) + old_xf_1 + 2 * pi)
          
       forall (j = 1: lats - 1) yf(j) = 0.5 * (yf(j) + yf(j+1))
    end if

  END SUBROUTINE conf_dat2d

end module conf_dat2d_m
1	guez	3	module conf_dat2d_m
2
3			! From conf_dat2d.F, version 1.2 2006/01/27 15:14:22
4
5			IMPLICIT NONE
6
7			contains
8
9			SUBROUTINE conf_dat2d(xd, yd, xf, yf, champd, interbar)
10
11			! Auteur : P. Le Van
12
13			! Ce sous-programme configure le champ de données 2D 'champd' et
14			! les longitudes et latitudes de telle façon qu'on ait - pi à pi
15			! en longitude et pi/2 à - pi/2 en latitude.
16
17			! This procedure receives a 2D field, with the corresponding
18			! coordinate variables: longitude and latitude.
19			! The procedure converts longitude and latitude to radians, if the
20			! input values are in degrees.
21			! If the input longitudes are between 0 and 2 pi, the procedure
22			! computes the congruent longitudes between -pi and pi, and permutes
23			! them so they stay in increasing order.
24			! If the input latitudes are from south pole to north pole, the
25			! procedure permutes them so they become from north to south.
26			! Any change on longitudes or latitudes induces a change on the 2D field.
27			! If required, the longitudes and latitudes are finally replaced
28			! by their mid-values.
29
30	guez	39	use nr_util, only: assert_eq, pi
31	guez	3
32			REAL, intent(in):: xd(:)
33			! (longitudes, in degrees or radians, in increasing order, from 0°
34			! to 360° or -180° to 180°)
35
36			REAL, intent(in):: yd(:)
37			! (latitudes, in degrees or radians, in increasing or decreasing
38			! order, from pole to pole)
39
40			LOGICAL, intent(in), optional:: interbar
41			REAL, intent(out):: xf(:), yf(:) ! longitudes and latitudes, in rad
42			REAL, intent(inout):: champd(:, :)
43
44			! Variables locales:
45
46			INTEGER lons, lats
47			LOGICAL radianlon ! "xd" is in degrees
48			logical invlon ! "xd" contains longitudes between 0 and 2 pi
49			logical radianlat ! "yd" is in rad
50			REAL rlatmin, rlatmax, old_xf_1
51			INTEGER i, j
52			logical mid_values
53
54			!------------------------------
55
56			lons = assert_eq(size(xd), size(xf), size(champd, 1), "conf_dat2d lons")
57			lats = assert_eq(size(yd), size(yf), size(champd, 2), "conf_dat2d lats")
58
59			IF (xd(1) >= - pi -0.5 .AND. xd(lons) <= pi + 0.5) THEN
60			radianlon = .TRUE.
61			invlon = .FALSE.
62			ELSE IF (xd(1) >= -0.5 .AND. xd(lons) <= 2 * pi+0.5) THEN
63			radianlon = .TRUE.
64			invlon = .TRUE.
65			ELSE IF (xd(1) >= -180.5 .AND. xd(lons) <= 180.5) THEN
66			radianlon = .FALSE.
67			invlon = .FALSE.
68			ELSE IF (xd(1) >= -0.5 .AND. xd(lons) <= 360.5) THEN
69			radianlon = .FALSE.
70			invlon = .TRUE.
71			ELSE
72			stop '"conf_dat2d": problem with longitudes'
73			ENDIF
74
75			rlatmin = MIN(yd(1), yd(lats))
76			rlatmax = MAX(yd(1), yd(lats))
77
78			IF (rlatmin >= -pi / 2 - 0.5 .AND. rlatmax <= pi / 2 + 0.5)THEN
79			radianlat = .TRUE.
80			ELSE IF (rlatmin >= -90. - 0.5 .AND. rlatmax <= 90. + 0.5) THEN
81			radianlat = .FALSE.
82			ELSE
83			stop '"conf_dat2d": problem with latitudes'
84			ENDIF
85
86			IF (radianlon) THEN
87			xf(:) = xd(:)
88			else
89			xf(:) = xd(:) * pi / 180. ! convert to rad
90			ENDIF
91
92			IF (radianlat) THEN
93			yf(:) = yd(:)
94			else
95			yf(:) = yd(:) * pi / 180. ! convert to rad
96			ENDIF
97
98			IF (invlon) THEN
99			! On tourne les longitudes pour avoir - pi à + pi :
100
101			! Get the index of the first longitude > pi:
102			i = 1
103			do while (xf(i) <= pi)
104			i = i + 1
105			end do
106
107			xf(i:) = xf(i:) - 2 * pi
108			xf(:) = cshift(xf, shift=i - 1)
109			champd(:, :) = cshift(champd, shift=i - 1)
110			ENDIF
111
112			IF (yd(1) < yd(lats)) THEN
113			! "yd" contains latitudes from south pole to north pole,
114			! reverse their order in "yf":
115			yf(lats:1:-1) = yf(:)
116			champd(:, lats:1:-1) = champd(:, :)
117			ENDIF
118
119			if (present(interbar)) then
120			mid_values = interbar
121			else
122			mid_values = .true. ! default
123			end if
124			if (mid_values) then
125			! Replace longitudes and latitudes by their mid-values:
126			old_xf_1 = xf(1)
127			forall (i = 1: lons - 1) xf(i) = 0.5 * (xf(i) + xf(i+1))
128			xf(lons) = 0.5 * (xf(lons) + old_xf_1 + 2 * pi)
129
130			forall (j = 1: lats - 1) yf(j) = 0.5 * (yf(j) + yf(j+1))
131			end if
132
133			END SUBROUTINE conf_dat2d
134
135			end module conf_dat2d_m