Help in averaging climate data

Sam
2013 6 6
2 个回答
更新时间：2015 7 14
16 次查看（30 天）

0 个投票

I am a novice in matlab and looking for help with calculating average monthly data from hourly data.
I have the data for full year in one file and have multiple txt files for different years. Column 1 is year, column 2 is month of year (1 to 12), column 3 is day of month and column 4 is hour of day (0 to 23). Looking forward to some guidance on how to do this.
Thanks in advance

5 个评论
显示 3更早的评论 隐藏 3更早的评论

Kye Taylor
Kye Taylor 2013-6-6
Have you imported the data into MATLAB? I.e. do you have the data stored in a N-by-4 dimensional matrix yet?
Kye Taylor
Kye Taylor 2013-6-6
So, does a row of the data looks like
[1990, 2, 28, 23] % for 11pm Feb 28 1990
Where is the climate data? Is that stored in another column? or a separate vector?
Sam
Sam 2013-6-6
This is how I imported the data to matlab:
D = importdata('metdata1.txt')
D =
data: [8760x13 double]
textdata: {8760x1 cell}
rowheaders: {8760x1 cell}
Kye Taylor
Kye Taylor 2013-6-6
So, which columns of the 13 are the four you describe above, and which one is the climate data?
Sam
Sam 2013-6-6
And this is what the first row looks like if I am doing it right:
D.data(1,:)
ans =
1.0e+03 *
Columns 1 through 12
1.9730 0.0010 0.0010 0 -0.9990 -0.0999 -0.0090 -0.9999 -0.9999 -0.9999 -0.9999 -0.0990
Column 13
-0.0990

请先登录，再进行评论。

请先登录，再回答此问题。

回答（2 个）

Sam
Sam 2013-6-6

0 个投票

Yes, I have imported them into matlab
Roger Stafford
Roger Stafford 2013-6-6

0 个投票

I'll suppose you have the climate data in column five of an array, A, with the year, month, day, and hour in its columns 1, 2, 3, and 4, respectively.
[u,~,ix] = unique(A(:,1:2),'rows');
B = [u,accumarray(ix,A(:,5))./accumarray(ix,1)];

5 个评论
显示 3更早的评论 隐藏 3更早的评论

Sam
Sam 2013-6-6
编辑：Sam 2013-6-6
Hi Roger, Thanks, this seems to produce a matrix for the 12 months. But how not to take into account the "999.9" data i.e. the missing value data in the column?
Roger Stafford
Roger Stafford 2013-6-6
It should produce a row for every year-month combination, not just for 12 months.
If you can fully(!) describe the "missing value" situation, perhaps a solution could be found. As things stand, I can only guess at what you mean.
Sam
Sam 2013-6-6
Actually data for different years are in different files in the data column, a data value of "999.9" means a missing value so not to be considered in the a calculation. Now it is averaging over the entire column for unique values of month.
Roger Stafford
Roger Stafford 2013-6-6
You could initially remove all rows with the "999.9" data values:
A = A(A(:,5)~=999.9,:);
However, it might be better to allow some tolerance for rounding differences:
A = A(abs(A(:,5)-999.9)<100*eps(999.9),:);

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Climate Science and Analysis 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