This detail in these functions is pretty obscure. The functions
could be made friendlier by checking the grid of the third
argument, and if it's 1-D just go ahead, and not insist it's in
any particular direction, but there we are. Glad to hear it's
working for you.|
On 5/7/2018 10:31 AM, Pearse J.
Hello Ansley and others,
This works! Thanks for the help.
So to clarify: Ysequence, and the other sequences (Xsequence,
Zsequence, etc), simply tell ferret that I want some numbers
placed on a certain axis?
Replying to the list as well -- Pearse and I looked at
this a bit. The error message is
Bailing out of external function "scat2gridgauss_yz":
No data in scattered y, z points. F()
data values must be defined on Y or Z axis.
**ERROR: error in external function
The arguments to the function are SCAT2GRIDGAUSS_YZ(YPTS,
ZPTS, F, YAXPTS, ZAXPTS, ...)
where ypts and zpts are simple lists of
points, on any axis. The third argument, F, can also
depend on other dimensions. This would allow for you to
have a set of locations ypts, zpts, and F as a measurement
at a set of times and/or a set of longitudes. This means
that for the third argument, the scattered-data direction
must lie along a y or z axis. The function then keeps any
dependence on an X, T, E, or F axis, and finds the
"scattered" data along a Y or Z direction. In the
F-data: 3rd component of scattered input
triples. This is the variable we are putting onto the
grid. It must have the scattered-data direction along a
Y or Z axis. May be function of X or time.
For this case, all you need to do is recast the data for the
3rd argument onto a Y or Z axis,
yes? define axis/y=-65:25:1/units=degrees
yes? define axis/z=0:6000:50/units=meters/depth
yes? let xscale = 0.5
yes? let yscale = 25
yes? let cutoff = 3
yes? let no3_ind_on_y = YSEQUENCE(no3_ind)
yes? let no3int_ind = scat2gridgauss_yz(lat_ind,
dep_ind, no3_ind_on_y, y[gy=yax], z[gz=zax], xscale,
yscale, cutoff, 0)
yes? shade no3int_ind
On 5/4/2018 10:05 AM, Ansley C.
For your data, the arguments of scat2gridgauss_yz would
just be the simple 1-D lists of data, and the result
will be on your y-z grid defined by the axes yax and zax
that you've defined. The function allows for the 3rd
argument to have more dimensions, for instance scattered
locations all measured at a set of times, but it is fine
for the first 3 arguments to all be 1-D.
You're treating longitude only as a mask, that is
keeping longitudes in the range between 35 and 120
degrees east, correct? So the result will not depend on
Since z is a depth, you should define your axis zax
with /depth, that is positive values of depth increasing
downwards. You don't say what error you're running
into. What plot commands are you trying and what
On 5/4/2018 8:03 AM, Pearse
I’m trying to interpolate
observations of NO3 using the function
I successfully read in my data,
which is structured as 1D column data, which looks
As you can see, I have 37,200
I now want to select my data from
the Indian Ocean, where I eventually would like to
do my interpolation using scat2gridgauss_yz.
Plotting the locations it seems
like this has worked nicely.
However, the problem then arises
when I want to use “scat2gridgauss_yz” to
interpolate this data. My command is:
And when trying to plot the data,
I have an error. This error is related (I think!) to
the fact that my NO3 data is in a 1D
form. That is, it doesn’t have y,z coordinates.
Scat2gridgauss requires that the variable in the 3rd
argument be of 2 dimensions. Specifically, it must
relate to the 2 dimensions of the 1st and
2nd arguments, in this case Latitude and
My question, therefore, is how to
place my 1D NO3 data onto 2 dimensions of
the lat,depth coordinates.
Pearse J. Buchanan
Institute for Marine and Antarctic
Studies (IMAS), University of Tasmania
PhD Candidate / CSIRO-UTAS
Quantitative Marine Science
ARC Centre of Excellence in Climate
System Science – UTAS student representative
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