I tried to see the MatLab documentation here:
http://www.mathworks.com/help/matlab/ref/interp3.html
and then in
help interp3
in MatLab, but it's hard for me to understand what I really want, and if interp3 is what I'm looking for. But maybe I just don’t understand if I can use interp3 with the way I have everything at the moment. I have attached a number that I can create from the MatLab program that I wrote. It takes NOAA lat / long (x / y), U / V directions for the wind vectors, and then the Z value for the 2D levels in this field.
Using format:
quiver3(x,y,z,u,v,w)
with component "W" set to 0.
This is a very small part of the field, but I'm trying to interpolate between these two-dimensional vector fields to create a 3D field.
Do I need to group U / X, V / Y and W / Z into my own vectors in order to use interp3? I'm still not sure that the "V" section in the 3D function is in interp3 syntax
Vq = interp3(X,Y,Z,V,Xq,Yq,Zq)
This is a very small part of the field, but I'm trying to interpolate between these two-dimensional vector fields to create a 3D field.
My code is:
tic clc clear all % You will have to change the directory to wherever you place the read_grib.r4 % file. In addition, It necessary to have an external compiler connected % to MatLab in order to build the mex-file that gives you the power to use % the read_grib decoding. This is really tricky. On OSX I used Xcode as an % environment and MatLab virtually worked immediately. On Windows, I have % 2012(b) and had to use the call system('mxvc <BDS_unpack_mex5.c>') which % utilized Microsoft C-compiler that I had SOMEWHERE on my computer % thankfully (may be pre-intalled). There are tutorials online for % different compilers. In addition, if you're smart about it you can add % the mex-file build to the start-up operations so you never have to worry % about it, but my questionably legal MatLab copies seem to make this a % little more difficult. cd /Users/Sargent_PC/Downloads/read_grib.r4/ mex BDS_unpack_mex5.c % ** Inventory doesn't need to be done every iteration ** % ** Uncomment the line below to get a record inventory ** %read_grib('NOAAdata.grb','inv'); % Creating a struct named "grib_struct" for each of the records I'm % extracting out of the grib file. They exist in pairs with 6 records % separating them. Should we want to extract ALL of the U and V wind % components I'll iterate with a simple for-loop. grib_struct=read_grib('NOAAdata.grb', [60,61,66,67]); %,72,73,78,79,84,85,90,91,96,97]); UwindVec50mb = grib_struct(1).fltarray; %rec60 VwindVec50mb = grib_struct(2).fltarray; %rec61 UwindVec75mb = grib_struct(3).fltarray; %rec66 VwindVec75mb = grib_struct(4).fltarray; %rec67 % UwindVec100mb = grib_struct(5).fltarray; %rec72 % VwindVec100mb = grib_struct(6).fltarray; %rec73 % UwindVec125mb = grib_struct(7).fltarray; %rec78 % VwindVec125mb = grib_struct(8).fltarray; %rec79 % UwindVec150mb = grib_struct(9).fltarray; %rec84 % VwindVec150mb = grib_struct(10).fltarray; %rec85 % UwindVec175mb = grib_struct(11).fltarray; %rec90 % VwindVec175mb = grib_struct(12).fltarray; %rec91 % UwindVec200mb = grib_struct(13).fltarray; %rec96 % VwindVec200mb = grib_struct(14).fltarray; %rec97 %50mb range has records 60 and 61 for U and V respectively. %75mb range has records 66 and 67 for U and V respectively. %100mb range has records 72 and 73 for U and V respectively. %125mb range has records 78 and 79 for U and V respectively. %150mb range has records 84 and 85 for U and V respectively. %175mb range has records 90 and 91 for U and V respectively. %200mb range has records 96 and 97 for U and V respectively. %These extracted sections of the grib file will read "extracted" on the %left-hand side should they be successfully extracted. load NOAAlatlongdata; % read the data into a matrix lat_value = NOAAlatlongdata(:,3); % copy first column of NOAAlatlongdata into lat_value long_value = NOAAlatlongdata(:,4); % and second column of NOAAlatlongdata into long_value % I was going to add in a pressure to altitude change here, but % it may be in our best interest to get a list of values for each % pressure level that correspond to altitude and create our own % vector of those values in order to simplify the calculations that % the program has to do. % z50mb_val = ; % z75mb_val = ; % z100mb_val= ; % z125mb_val= ; % z150mb_val= ; % z175mb_val= ; % z200mb_val= ; % Creating vectors of the Z-values which are gotten from converting the % pressure value to altitude. I feel like this is a very bulky way to do % this, and I've included the tic-toc timing to show that it ~30seconds % per vector creation. For each altitude level that we add you'll add % ~30seconds JUST to the vector creation component of the program. tic; for i = 1:262792, z50mb_vec=67507*ones(i,1); end; toc; tic; for i = 1:262792, z75mb_vec=60296*ones(i,1); end; toc; % tic; for i = 1:262792, z100mb_vec=53084*ones(i,1); end; toc; % % tic; for i = 1:262792, z125mb_vec=48865*ones(i,1); end; toc; % % tic; for i = 1:262792, z150mb_vec=44646*ones(i,1); end; toc; % % tic; for i = 1:262792, z175mb_vec=43763*ones(i,1); end; toc; % % tic; for i = 1:262792, z200mb_vec=38661*ones(i,1); end; toc; % tic; for i = 1:262792, W_zerovec = 0*ones(i,1); end; toc; % % 3D quiver plots format: quiver3(x,y,z,u,v,w) -- Make sure dimensionality % of all 6 components to that plot match up before plotting. quiver3((lat_value(1:101)), (long_value(1:25)), ( z50mb_vec(1:25)), (UwindVec50mb(1:25)) ,(VwindVec50mb(1:25)) , W_zerovec(1:25)) hold on quiver3((lat_value(1:101)), (long_value(1:251)), ( z75mb_vec(1:25)), (UwindVec75mb(1:25)) ,(VwindVec75mb(1:25)) , W_zerovec(1:25)) hold on % quiver3((lat_value(1:101)), (long_value(1:101)), (z100mb_vec(1:101)), (UwindVec100mb(1:101)),(VwindVec100mb(1:101)), W_zerovec(1:101)) % hold on % quiver3((lat_value(1:101)), (long_value(1:101)), (z125mb_vec(1:101)), (UwindVec125mb(1:101)),(VwindVec125mb(1:101)), W_zerovec(1:101)) % hold on % quiver3((lat_value(1:101)), (long_value(1:101)), (z150mb_vec(1:101)), (UwindVec150mb(1:101)),(VwindVec150mb(1:101)), W_zerovec(1:101)) % hold on % quiver3((lat_value(1:101)), (long_value(1:101)), (z175mb_vec(1:101)), (UwindVec175mb(1:101)),(VwindVec175mb(1:101)), W_zerovec(1:101)) % hold on % quiver3((lat_value(1:101)), (long_value(1:101)), (z200mb_vec(1:101)), (UwindVec200mb(1:101)),(VwindVec200mb(1:101)), W_zerovec(1:101)) toc