my data is in following form:
days of week date time(hrs) visitors
mon jan 2 2010 900 501
mon jan 2 2010 1000 449
mon jan 2 2010 1100 612
likewise for every day for entire year. i need to create a matrix of days of week as shown below:
A=[
mon
mon
mon
]
Here is how I would read the tab-separated values, and parse the dates:
%# read and parse file
fid = fopen('data.csv','rt');
C = textscan(fid, '%s %s %s %d', 'Delimiter','\t', 'HeaderLines',1, ...
'MultipleDelimsAsOne',true, 'CollectOutput',false);
fclose(fid);
%# get date and number of visitors
dt = datenum(strcat(C{2}, {' '}, C{3}), 'mmm dd yyyy HHMM');
visitors = C{4};
%# plot
plot(dt,visitors)
datetick('x')
xlabel('time of day'), ylabel('visitors')
As for the day-of-week column, you can get it as:
>> C{1} %# first column from file
ans =
'mon'
'mon'
'mon'
>> cellstr(datestr(dt,'ddd')) %# actual day of week from parsed dates
ans =
'Sat'
'Sat'
'Sat'
this produces different days (either your data posted was simply made-up, or you have a bug in the part that generated those dates!)
Taking prompts from this previous question,
fid = fopen('filename.txt');
% Skip a line for the header
s = fgetl(fid);
% Read the rest into data
data = textscan(fid, '%s %s %d %d %d %d');
% Close the file
fclose(fid);
The days of the week are in the first cell of data
.
You could download my csvimport submission from the File Exchange. Assuming your data is tab separated, you can read it using:
[days datecol timecol visitors] = csvimport( 'file.txt', 'delimiter', '\t', ...
'columns', {'days of week', 'date', 'time(hrs)', 'visitors'} );
The first 2 output parameters will cell arrays of strings while the last 2 will be double matrices.
If you are just getting started with (a recent version of) matlab, the easiest way is to use the 'import wizard'.
A few simple steps:
- Browse to your file and right click it
- Choose the option to import
- Select the choice to store things as
cell array
(Vectors or matrices wont work). - Click Import
Optionally you can click next to import and select that you want to generate the code for this procedure. However, this will likely be a bit verbose. If you just need to do it once, I would recommend this method.
You could try to use dlmread
. It can take any ASCII delimiter. I think it might suit your requirements. See here.
来源:https://stackoverflow.com/questions/6759657/reading-text-data-from-a-csv-file-in-matlab