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我已經嘗試看看MatLab的文檔,這裏[場]:
http://www.mathworks.com/help/matlab/ref/interp3.html
然後在
help interp3
部分MatLab,但我很難找出我實際上想要什麼,如果interp3是我正在尋找的東西。但是,我可能不會理解我是否能夠像現在一樣使用interp3。我附上了一張我可以從我寫的MatLab程序創建的圖。它將採用NOAA緯度/經度(x/y),風矢量的U/V方向,然後是2D場的Z值。
使用格式:
quiver3(x,y,z,u,v,w)
設置爲0
這是該領域的一個很小的部分,但我想要做的是插值「W」組件在這些2D矢量場之間以創建3D場。
爲了使用interp3,我必須將U/X,V/Y和W/Z組合到它們自己的向量中嗎?我仍然不知道的是,3D功能的「V」部分是在
Vq = interp3(X,Y,Z,V,Xq,Yq,Zq)
這是該領域的一個很小的部分,但我想要做的是它們之間進行插值的interp3語法2D矢量場以創建3D場。
我的代碼:
tic
clc
clear all
% You will have to change the directory to wherever you place the read_grib.r4
% file. In addition, It's 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's 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's ~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
您的2D字段結構如何?它們是否都在同一個X-Y常規網格上,只有Z值發生變化? – Dan
對不起,這麼晚回到你身邊。它們與該字段中同一部分的lat/long - x/y值相同。把它看作試圖繪製同一領域的多個層次。 Z是壓力高度,所以這將隨着插值而變化,U和X在相同x/y(緯度/經度)值處的層之間變化,並且W將保持恆定爲零(不提供W分量)。所以基本上,如果我可以有選擇地在Z範圍內選擇矢量的U和V分量之間的插值(在這種情況下是兩個水平之間的距離),那麼我將填充3D空間,就像我期待的那樣。 –
無法編輯上面:U和V組件將在不同層次之間在相同的X/Y緯度/長度值,而不是U和X,抱歉混淆!我試圖填補多個2D張之間的差距通過線性插值,只是爲了澄清。 –