Reading text file
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Hi!
This seems like an easy one but I can never wrap my head around reading text files.
I have a text file which contains u and v components of wind and pressure for a cyclone at a certain grid point. Here's a snipet of the data...
GridID u wind v wind Pressure
159838 5.25 -1.6 1018.8
159839 5.19 -2.1 1018.8
159840 5.03 -2.5 1018.8
159841 4.76 -3.0 1018.8
159842 4.42 -3.3 1018.8
#
160945 5.13 -5.3 1018.5
160946 4.38 -5.4 1018.6
160947 3.66 -5.5 1018.7
160948 3.00 -5.3 1018.8
160949 2.42 -5.1 1018.8
160950 1.91 -4.8 1018.9
etc...
The # means that the following data is on another time step. Each timestep is a different size as the cyclone does not affect every grid cell. I want to load this data into a matrix.
Any suggestions on the best way to do this? Any help would be greatly appreciated :)
采纳的回答
Fangjun Jiang
2011-10-3
One way to do it.
clear;
fid=fopen('test.txt');
str=textscan(fid,'%s','headerlines',1);
fclose(fid);
str=str{1};
str=[{'#'};str;{'#'}];
index=find(strcmp(str,'#'));
N=length(index);
Data=cell(N-1,1);
for k=1:N-1
Data{k}=reshape(str2double(str(index(k)+1:index(k+1)-1)),4,[])';
end
>> Data
Data =
[5x4 double]
[6x4 double]
[3x4 double]
>> Data{1}
ans =
1.0e+005 *
1.598380000000000 0.000052500000000 -0.000016000000000 0.010188000000000
1.598390000000000 0.000051900000000 -0.000021000000000 0.010188000000000
1.598400000000000 0.000050300000000 -0.000025000000000 0.010188000000000
1.598410000000000 0.000047600000000 -0.000030000000000 0.010188000000000
1.598420000000000 0.000044200000000 -0.000033000000000 0.010188000000000
>> Data{2}
ans =
1.0e+005 *
1.609450000000000 0.000051300000000 -0.000053000000000 0.010185000000000
1.609460000000000 0.000043800000000 -0.000054000000000 0.010186000000000
1.609470000000000 0.000036600000000 -0.000055000000000 0.010187000000000
1.609480000000000 0.000030000000000 -0.000053000000000 0.010188000000000
1.609490000000000 0.000024200000000 -0.000051000000000 0.010188000000000
1.609500000000000 0.000019100000000 -0.000048000000000 0.010189000000000
>> Data{3}
ans =
1.0e+005 *
1.609450000000000 0.000051300000000 -0.000053000000000 0.010185000000000
1.609460000000000 0.000043800000000 -0.000054000000000 0.010186000000000
1.609470000000000 0.000036600000000 -0.000055000000000 0.010187000000000
更多回答（1 个）
Walter Roberson
2011-10-3
We need more information about how you want this stored. You say you want the data stored in a matrix, but do you want all of the data stored in a single matrix, ignoring the '#' boundaries, or do you want one matrix (or at least one cell) for each section ?
If you want everything in one matrix ignoring the '#', then
fid = fopen('YourFile.txt', 'rt');
datacell = textscan('%f%f%f%f', 'HeaderLines', 1, 'CombineOutput', 1, 'CommentStyle', '#');
fclose(fid);
data = datacell{1};
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