The lists of numbers in bx and by do not tell Ferret that they
are longitudes and latitudes. So Ferret does not know to apply
a "modulo" operation to convert -17 to (360-17) and put it at the
right location on the plot. You can easily do the modulo operation
yourself on the values in bx:
let modbx = if bx lt 0 then 360+bx else bx
polygon/line/over modbx, by
Emilie Vanvyve wrote:
Thanks for the answers I got to my Friday questions! With them, I
could finally find an "enough-simple-according-to-me" way to solve my
little problem (I agree it is indeed easier to write to/read from a
But I now encounter another one when I use POLYGON when a region has
been defined: the polygon is not plotted as soon as I restrict the x
and/or y-axis values (with: set region, /x=...:..., /y=...:...),
otherwise it is plotted.
It may be comprehensible, but I do not know how to put up with that.
Briefly, I do within a script:
region/x=31.7W:33.7E/y=32.5N:64.9N !Europe instead of whole world
my_var !Europe instead of whole world
where bx and by are both 1-D arrays, containing resp. longitude and
latitude values of a shape I wish to draw on the plot.
They are e.g. (read from the box.dat file):
yes? list bx, by
DATA SET: ./box.dat
X: 0.5 to 348.5
Column 1: BX
Column 2: BY
1 / 1: -17.00 32.53
2 / 2: -17.08 32.87
3 / 3: -17.17 33.21
4 / 4: -17.26 33.55
5 / 5: -17.35 33.89
344 / 344: -15.38 32.81
345 / 345: -15.78 32.74
346 / 346: -16.19 32.67
347 / 347: -16.59 32.60
348 / 348: -17.00 32.53
I suspect the problem to be directly linked to the restriction I
impose on x and/or y-axis values, when I define the region. Those
restrictions might in fact be also applied to bx and by. Their index 1
to 348 seem to be understood as longitudes.
I tried to give the bx and by values according another axis:
but it did not work.
What's the solution...?
Thanks in advance for any suggestion!
Physicist, PhD student
Université catholique de
Institut d'astronomie et de géophysique G. Lemaître (ASTR)
Chemin du Cyclotron, 2
1348 Louvain-la-Neuve (Belgium)
Phone : +32-(0)10-473300
Fax : +32-(0)10-474722
E-mail : email@example.com
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