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?
Pearse
From: Ansley C. Manke [ansley.b.manke@xxxxxxxx]
Sent: 07 May 2018 13:16
To: ferret_users@xxxxxxxx
Subject: Re: [ferret_users] putting 1D variable into 2D (lat,depth) for using in objective analysis
Hi Pearse,
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
http://ferret.pmel.noaa.gov/Ferret/documentation/usersguide/variablesxpressions/XPRESSIONS#_SCAT2GRIDGAUSS_YZ
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 scattereddata 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 documentation,
Fdata: 3rd component of scattered input triples. This is the variable we are putting onto the grid. It must have the scattereddata 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 yax
yes? define axis/z=0:6000:50/units=meters/depth zax
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
Ansley
On 5/4/2018 10:05 AM, Ansley C. Manke wrote:
Hi Pearse,
For your data, the arguments of scat2gridgauss_yz would just be the simple 1D lists of data, and the result will be on your yz 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 1D.
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 longitude.
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 happens?
Ansley
On 5/4/2018 8:03 AM, Pearse Buchanan wrote:
Hello all,
I’m trying to interpolate observations of NO_{3} using the function “scat2gridgauss_yz”.
I successfully read in my data, which is structured as 1D column data, which looks like so:
As you can see, I have 37,200 observations.
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 NO_{3} data is in a 1D form. That is, it doesn’t have y,z coordinates. Scat2gridgauss requires that the variable in the 3^{rd}
argument be of 2 dimensions. Specifically, it must relate to the 2 dimensions of the 1^{st} and 2^{nd} arguments, in this case Latitude and Depth.
My question, therefore, is how to place my 1D NO_{3} data onto 2 dimensions of the lat,depth coordinates.
Thanks all,
Pearse
Pearse J. Buchanan
Institute for Marine and Antarctic Studies (IMAS), University of Tasmania
PhD Candidate / CSIROUTAS Quantitative Marine Science
ARC Centre of Excellence in Climate System Science – UTAS student representative
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