Variable names in loop?
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Hey, I am trying to extract some environmental parameter measurements from netcdf format file and importing them to an excel file. Here is my code:
fullname={'india-20140101-ssrd-run00.nc'};
Varname='var169';
vardata=ncread(fullname,Varname);
i=1;
while i<26
sheet=i;
filename='india-20140101-ssrd-run00.xlsx';
xlRange='B4:IH244';
xlswrite(
filename,vardata(:,:,i),sheet,xlRange);
i=i+1;
end;
I have to read data from several files with names:
india-20140102-ssrd-run00.nc india-20140103-ssrd-run00.nc india-20140104-ssrd-run00.nc india-20140105-ssrd-run00.nc . . .
Is it possible to employ a loop here?
采纳的回答
Chad Greene
2015-3-31
There are a couple of ways you can do this. One way is to populate a list of names manually before starting the loop:
filenames = {'my file 1'; 'my other file'; 'somebody else''s file'};
for k = 1:length(filenames)
disp(filenames{k})
end
Or if you're only incrementing numbers you can do it like this:
for k = 10:13
fullname = ['myfilenumber_',num2str(k),'.nc'];
disp(fullname)
end
4 个评论
sujit
2015-3-31
N = 1e5;
tic
for k = 1:N
['myfilenumber_',num2str(k),'.nc'];
end
toc
tic
for k = 1:N
sprintf('myfilenumber_%i.nc',k);
end
toc
Elapsed time is 5.014318 seconds.
Elapsed time is 0.923741 seconds.
It is a good habit to learn to use sprintf rather than string concatenation!
Chad Greene
2015-3-31
That's awesome, Stephen!
sujit
2015-4-19
更多回答（1 个）
Brendan Hamm
2015-3-31
Sure there are multiple ways to do this.
1. Assuming all of the files are in the same directory (I assume the working) we can use the command:
fileList = dir('india-*'); % Returns a struct with info on the files that begin with 'india-'
fileNames = {fileList.name}; % Extract the file names into a cell array;
for k = 1:length(fileNames)
xlsread(fileNames{k},...); % Fill in the rest here
% Perform more operations here
end
2. You could just start the loop at 20140101 and use strcat. I would use the first method, so will not elaborate here.
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