Stacking 2D matrix to 3D using time as a third variable

2022 12 9
1 个回答
回答已采纳
更新时间：2022 12 12
3 次查看（30 天）

0 个投票

Hi I am a beginner in matlab and I am trying to stack 2D matrix into 3D matrix. I have variable sst as 1440*720 and time variable as 1*366. These are all daily data. How do I stack time to sst so that I have 366*1440*720 matrix. I have tried using cat and meshgrid but nothing seems to work. Thank you.
data.time = cat(3,data.time,data.sst)
or
[data.sst1]=meshgrid(data.sst,data.time); (this multiplies 1440*720 and gives me 366*1036800 matrix)

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Voss
Voss 2022-12-9
To end up with a 366*1440*720 array, you would need 366 individual 1440*720 matrices. In other words, you need a 1440*720 matrix for each time value. But it seems that you have one 1440*720 matrix and one scalar for each time value.
Put another way: a 366*1440*720 array has 366*1440*720 = 379,468,800 elements, but you have 366 + 1440*720 = 1,037,166 elements, not enough for a 366*1440*720 array.
If you had 366 individual 1440*720 matrices, then you could stack (and reshape/permute) them into a 366*1440*720 array (or a 1440*720*366 array, or whatever, as long as there's still 379,468,800 elements), but it doesn't seem like that's what you have.
Ashal
Ashal 2022-12-9
编辑：Ashal 2022-12-9
Thank you. I do have individual 366 1440*720 and I am using the following code to read data. So basically I have 366 different files that has sst(1440*720) and time values Here ii =366. I wish I could add data here but it is a huge folder.
gunzip("2020.zip.gz")
!ls 2020/oisst-*.nc>data.ptr
x = importdata('data.ptr'); %here x is cell array
for ii = 1:length(x);
data.time(ii) = ncread(x{ii},'time');
%ncdisp("2020/oisst-avhrr-v02r01.20200101.nc"); %ncdisp look inside nc file
data.sst = ncread(x{ii}, 'sst');
end
Peter Perkins
Peter Perkins 2022-12-12
Just out of curiousity ...
366, OK, days in 2020 (although you may have a bug when you work on a non-leap year)
1440, OK, so maybe 24*60 minutes in a day?
What does 720 represent?
Or is 1440x720 a spatial lat/lon grid?

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Voss
Voss 2022-12-9
编辑：Voss 2022-12-9

0 个投票

nx = numel(x);
data = struct( ...
'time',zeros(1,nx), ...
'sst',zeros(nx,1440,720);
for ii = 1:nx
data.time(ii) = ncread(x{ii},'time');
%ncdisp("2020/oisst-avhrr-v02r01.20200101.nc"); %ncdisp look inside nc file
data.sst(ii,:,:) = ncread(x{ii}, 'sst');
end
That makes data.sst a 366*1440*720 array, as requested.

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 App Building 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by