I want from a csv archive to read only one column. The problem is that I want to read this column from the second line and by using these commands:
[d1,tex]= xlsread(filename1);
name=tex(:,4)
it's reading from the first line.
Also, I would like to create a matrix that will inclue two columns that have come from commants (equations etc) in my Matlab code.
xlsread is deprecated by MathWorks. Try using readtable in the future.
To your original question, I'm assuming that you want to read everything in the 4th column from the second row onward. If so, your second line is incorrect:
name = tex(2:end,4)
Without further example code, I can't answer the rest of your question. Add some details and I'll see what I can do.
I have a long file, and I want to read a specific line not from the first sequence lines.
is there a way to do it without looping all over the file and counting the lines?
For example files.read, which get an index from which line to read?
Thanks
You can use the predefined method files.get_text_lines().
I have a lot of .txt files (<1000 lines each). The data format is the following (the picture): there are some lines in the beginning that I don't need, then the line with '', then the lines with data that I need to extract from the file, then again a line with '' and some comments that I don't need.
Is there any way to do that? I have a lot of such files. The matter is that in every file the number of lines before the first '' is different. So, is there any way to read the data in between of two ''? I tried all the functions but I am a beginner and just cannot come up with the right idea...
This is quite simple with regular expressions:
usefulData = regexp(fileread('abg06.txt'), '(?<=\*).*?(?=\*)', 'match','once');
I have a large .csv file (~26000 rows). I want to be able to read it into matlab. Another problem is that it contains a collection of strings delimited by commas in one of the fields.
I'm having trouble reading it. I tried stuff like tdfread, which won't work here. Any tricks with textscan i should be aware about?
Is there any other way?
I'm not sure what is generating your CSV file but that is your problem.
The point of a CSV file, is that the file itself designates separation of fields. If the text of the CSV contains commas, then nothing you can do will help you. How would ANY program know when the text in a single field contains commas, or when that comma is a field delimiter?
Proper CSV would have a text qualifier. Some generators/readers gives you the option to use one. The standard text qualifier is a " (quote). Its changeable, though, because your text may contain those, too.
Again, its all about generating proper CSV content.
There's a chance that xlsread won't give you the answer you expect -- do the strings always appear in the same columns, for example? I think (as everyone else seems to :-) that it would be more robust to just use
fid = fopen('yourfile.csv');
and then either textscan
t = textscan(fid, '%s', delimiter', sprintf('\n'));
t = t{1};
or just fgetl (the example in the help is perfect).
After that you can do some line-by-line processing -- using textscan again on the text content of each line, for example, is a nice, quick way to get a cell-array that will allow fast analysis of each line.
You have a problem because you're reading it in as a .csv, and you have commas within your data. You can get it in Excel and manipulate the date, possibly extract the unwanted commas with Excel formulas. I work with .csv files for DB imports quite a bit. I imagine matLab has similar rules, which is - no commas in your data.
Can you tell us more about your data? Are there commas throughout, our just one column? Maybe you can read it in as tab delimited?
Are you using a Unix system? The reason I am asking is that you could use a command-line function such as sed and regular expressions to clean those data files before you pass them into Matlab. Here is a link that explains how to do exactly what you are looking for.
Since, as others have observed, your file is CSV with commas inside what you think of as a single field, it's going to be hard to persuade Matlab that that really is only one field. I think your best strategy is going to be to read one line at a time, into a string acting as a buffer, and to translate it, field-by-field, into the variables or other data structures that you want. Since Matlab has in-built regular expression capabilities this shouldn't be too hard.
And, as others have already suggested, posting a sample of your data would help us to help you.
One easy solution is:
path='C:\folder1\folder2\';
data = 'data.csv';
data = dataset('xlsfile',sprintf('%s\%s', path,data));
Of course you could also do the following:
[data,path] = uigetfile('C:\folder1\folder2\*.csv');
data = dataset('xlsfile',sprintf('%s\%s', path,data));
now you will have loaded the data as dataset. An easy way to get a column 1 for example is
double(data(1))
I need to open a text file and convert it into a CSV file in Matlab. The first 3 lines of the text file are sentences that need to be omitted. The next 28 lines are numbers that need to make up the first column of the CSV, and then the next 28 lines need to make up the second column.
The text file is called datanal.txt and the output file can be named anything. Any help would be appreciated.
Don't have Matlab now to test, but try this. Your input file should be in Matlab's current directory, or put the full path to the file name.
A = csvread('datanal.txt',3,0);
A = reshape(A,28,2);
csvwrite('output.csv',A)
well you can add #'s in front of the first 3 lines then use load and a reshape. Did you need a fully automated script or is there only one file? If you're familiar with matlab at all there are a bunch of ways to turn that large column vector into a matrix.