overlay of sampling locations

[Cyndy Chandler <cchandler@xxxxxxxx>]

Hello ferreters,

I'm trying to overlay some sampling locations on a map of the world, and
would appreciate some help ...

I was successful at doing an overlay plot of some sampling locations on
a map of the world with region /x=-180:180/y=-90:90 but I wanted to make
the map edge at 100E (because of the distribution of my data), and can't
figure out how to do an overlay plot on that 100W centric base map
(/x=100E:100E).  The base map looks fine, but the sampling location data
is still geing plotted on an x=-180:180 axis.

I've played around with various offsets to the longitudes of my sampling
locations, but all such attempts were unsuccesful, I think because that
longitude axis is not modulo.

I've attached the ferret script and sampling location datafile.

Can anyone tell me what I'm missing here?

Thanks much, Cyndy
! Make map of world 
! add lon, lat data points as red dots
! (modified from FUG and LAS FAQ scripts)
! 031007.clc.
!
! Usage:
! ferret  [ -gif after interactive mode messing about ]
!         [ -gif creates better res gif image ]
!   go map_sed_trap
!
! Product:
!  creates map_sed_trap.gif
! 
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

! set up environment
!
set mem/size=60
set win/size=.5

! world topo data source
! etopo60  first, then etopo20 for final image
!
!use etopo20
use etopo60
!show data/all

! color the whole world beautiful
! 
palette dark_land_sea
!set region/x=-180:180/y=-90:90  ... this one works
! but next one is better view for trap site distribution
! make the world begin in ... Bangkok
set region/x=100E:100E/y=-90:90
! set region/x=100:460/y=-90:90   .. this made the map I wanted, but
! how to adjust trap_lon? +280 (0:360 + 100 = 100:460)

! set up for Plate Caree map of the world
!
go mp_plate_caree
set grid rose

! Adjust the window aspect ratio
!
go mp_aspect

! Create the underlay map
!
shade/nokey/lev=(-10500,-5500,5000)(-5500,0,500)(0,2000,250)(2000,6000,1000)/nolab rose, x_page, y_page

! Lyme prevention: tics begone
!
ppl size ($ppl$xlen),($ppl$ylen)
ppl axlen ($ppl$xlen),($ppl$ylen)
ppl origin 0,0
shade/nokey/lev=(-10500,-5500,5000)(-5500,0,500)(0,2000,250)(2000,6000,1000)/nolab rose, x_page, y_page

! Get the trap lon and lat location data
!
file/var="trap_lat,trap_lon" trap_locs.dat

! mess with the data as needed
!
! convert longitudes from -180:180 to 0:360 degrees
!let lon = trap_lon + 180
! convert longitudes from -180:180 to 100:460 degrees
!let lon = trap_lon + 280
! convert longitudes to 100W centric world
!let lon = trap_lon[x=100E:100E]
!list lon[I=1:137]
!
let lat = trap_lat
let lon = trap_lon


! Plot the locations
! as small red dots (lox pox)
! use Map projection version of polymark.jnl
!     for working with map projection scripts
!
go mp_polymark POLY/OVER/NOLAB/NOAXES/NOKEY/PALETTE=red lon, lat, , circle, 0.5

! save plot to gif file
!
frame/file=map_sed_trap.gif
78.86	1.37
78.90	6.70
74.58	-6.73
70.00	-1.96
69.50	10.00
65.52	-0.10
75.86	11.47
73.00	19.00
47.72	-20.87
33.82	-21.02
32.73	-70.82
23.20	-63.98
32.08	-64.25
13.50	-54.00
1.80	-11.13
-2.18	-9.90
70.00	0.00
72.50	-8.00
68.00	-12.66
25.30	-79.50
54.58	-21.15
47.83	-19.50
47.82	-19.75
33.15	-21.98
31.55	-24.67
29.13	-15.43
28.00	-21.98
24.55	-22.83
21.98	-25.23
21.15	-20.68
20.92	-19.75
19.00	-20.17
11.48	-21.03
31.54	-55.92
-5.00	-25.00
-8.00	-28.00
-20.05	9.16
-20.00	-10.00
16.00	60.00
14.00	64.00
15.00	68.00
17.45	89.60
15.23	89.17
13.15	84.37
4.46	87.30
17.69	58.85
17.40	58.80
17.21	59.59
15.10	61.50
10.00	65.01
-76.49	-177.87
-73.54	176.89
-74.50	180.00
-66.16	-168.67
-63.15	-169.90
-60.28	-170.06
-56.90	-170.17
-53.03	-174.73
-57.00	-37.00
-62.26	-57.53
-62.44	-34.76
-64.92	-2.50
-50.67	68.60
-50.09	5.77
-54.34	-3.34
-64.90	-2.56
-47.00	141.50
-51.00	141.50
-61.55	150.45
-42.00	178.50
-44.00	178.50
58.00	179.00
53.00	149.00
9.00	-140.00
5.00	-140.00
2.00	-140.00
0.00	-140.00
-2.00	-140.00
-5.00	-140.00
-12.00	-135.00
50.00	-145.00
49.00	-138.00
1.04	138.94
11.06	140.14
42.19	-127.58
41.55	-132.00
39.49	-127.69
47.97	-128.10
42.09	-125.77
6.57	-92.77
8.83	-103.98
15.00	-151.00
0.00	175.16
7.93	175.01
34.42	177.74
30.00	175.00
37.40	174.95
46.12	175.03
4.13	136.28
1.22	160.57
39.67	132.40
53.50	-177.00
49.00	-174.00
5.35	-81.88
12.83	-103.90
34.17	141.98
27.88	-111.66
26.03	-110.92
34.23	-120.03
33.55	-118.50
18.47	116.02
14.60	115.10
5.01	138.83
12.01	134.29
44.07	155.03
15.00	175.02
22.75	-158.00
51.50	165.00
45.00	165.00
45.00	-177.00
36.73	-122.05
40.50	142.48
40.46	146.03
30.03	174.98
13.00	175.00
40.00	145.43
46.82	162.12
27.00	127.00
25.00	127.00
77.50	-150.00
78.00	-132.00
79.39	-102.65
42.73	8.52
42.25	32.62
43.18	32.02
43.00	34.00
42.35	37.57
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n:Chandler;Cyndy
tel;cell:508-274-0283
tel;fax:508-457-2161
tel;home:508-540-4957
tel;work:508-289-2765
x-mozilla-html:TRUE
url:http://usjgofs.whoi.edu/general_info/data_management.html
org:Department of Marine Chemistry and Geochemistry;Woods Hole Oceanographic Institution
adr:;;MS 43;Woods Hole;MA;02543;USA
version:2.1
email;internet:cchandler@whoi.edu
title:US JGOFS Data Management Office
note;quoted-printable:Office: GEOSECS room 14=3B =0D=0AHours: M-F 8:30-4:00
x-mozilla-cpt:usjgofs.whoi.edu;-13472
fn:Cyndy Chandler
end:vcard