Hi Jonathan,
The easiest way to make a second variable is to have it inherit the
grid from the first. Do you already have your small 3x2 region defined
on a grid in Ferret?
For instance, say we take a subset of an existing variable on a grid
yes? use etopo60
yes? let little_data = rose[i=45:47,j=133:134]
yes? list little_data
VARIABLE : ROSE[I=45:47,J=133:134]
FILENAME : etopo60.cdf
FILEPATH : /home/porter/tmap/ferret/linux/fer_dsets/data/
SUBSET : 3 by 2 points (LONGITUDE-LATITUDE)
64.5E 65.5E 66.5E
45 46 47
43.5N / 134: 195.0 184.9 175.4
42.5N / 133: 294.5 253.8 209.2
! Now make a list of the values you're going to divide by. We'll use
! RESHAPE to put them on the same grid as the first variable.
yes? let divide_by = {1,2,3,4,5,6}
yes? let divide_by_this = RESHAPE(divide_by, little_data)
yes? list divide_by_this
VARIABLE : RESHAPE(DIVIDE_BY, LITTLE_DATA)
FILENAME : etopo60.cdf
FILEPATH : /home/porter/tmap/ferret/linux/fer_dsets/data/
SUBSET : 3 by 2 points (LONGITUDE-LATITUDE)
64.5E 65.5E 66.5E
45 46 47
43.5N / 134: 4.000 5.000 6.000
42.5N / 133: 1.000 2.000 3.000
! Now you can divide the two:
yes? list little_data/divide_by_this
VARIABLE : LITTLE_DATA/DIVIDE_BY_THIS
FILENAME : etopo60.cdf
FILEPATH : /home/porter/tmap/ferret/linux/fer_dsets/data/
SUBSET : 3 by 2 points (LONGITUDE-LATITUDE)
64.5E 65.5E 66.5E
45 46 47
43.5N / 134: 48.7 37.0 29.2
42.5N / 133: 294.5 126.9 69.7
If you need to define grids, then take a look at DEFINE AXIS, and
DEFINE VARIABLE, and get back to us if you have more questions.
Ansley
Jonathan Winter wrote:
I have a small region, 3x2 points, that I would like to divide by a 3x2
grid of values that I manually set. My question is how to create the
grid of values to divide by? This can either be building the 3x2 array
from scratch or copying the original 3x2 array (using the "LET" command)
and reassigning the values. In MATLAB it would look like this:
my_vals = [1 2; 3 4; 5 6]
my_div = [2 1; 3 2; 1 2]
my_vals./my_div
Thanks in advance for the help,
jonathan
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