I have a .mat file which contains a struct (called wiki),
in which there is a field called full_path containing data as follows:
ans =
Columns 1 through 4
{'17/10000217_198…'} {'48/10000548_192…'} {'12/100012_1948-…'} {'65/10001965_193…'}
Columns 5 through 8
{'16/10002116_197…'} {'02/10002702_196…'} {'41/10003541_193…'} {'39/100039_1904-…'}
and so on
How can I create a .csv file with the data present in the curly braces?
This is quite a common problem, which requires very basic functions:
wiki = struct2array(load('wiki.mat', 'wiki'));
fid = fopen('q52688399.csv', 'w');
fprintf(fid,'%s\n', wiki.full_path{:});
fclose(fid);
The above will produce a ~2MB text tile containing a single column of strings.
Related
I have a deco.csv file and I only want to extract B1 to K1 (20 columns of the first rows), i.e. Deco_0001 to Deco_0020.
I first make a pre-allocation:
names = string(20,1);
and what I want is when calling S(1), it gives Deco_0001; when calling S(20), it gives Deco_0020.
I have read through textscan but I do not know how to specify the range is first row and running from column 2 to column 21 of the csv file.
Also, I want save the names individually but what I have tried just save the first line in only one cell:
fid=fopen('deco.csv');
C=textscan(fid, '%s',1);
fclose(fid);
Thanks!
It's not very elegant, but this should work for you:
fid=fopen('deco.csv');
C=textscan(fid, '%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s',1,'Delimiter',',');
fclose(fid);
S = cell(20,1);
for ii = 1:20
S{ii} = C{ii+1};
end
I am trying to load variables from a .dat file I have created.
The file is in the following format:
x = 1
y = 2
z = 3
I understand that if the file was in the format:
1 2 3
I could use
s = load(filename.dat)
and it would create an array with name 'S' storing all the numbers in the file.
However, from the first format I showed, I would like each stored as a separate variable.
I know I could do this with a .MAT file but this isn't really optimal to my requirements because it needs to be easily edited, preferably with notepad or another word processor.
Try textread function:
[varNames, varValues] = textread('tmp.txt', '%s%f', 'whitespace','\n', 'delimiter','=');
disp(varNames);
'x '
'y '
'z '
disp(varValues);
1
2
3
I have a .txt file with rows consisting of three elements, a word and two numbers, separated by commas.
For example:
a,142,5
aa,3,0
abb,5,0
ability,3,0
about,2,0
I want to read the file and put the words in one variable, the first numbers in another, and the second numbers in another but I am having trouble with textscan.
This is what I have so far:
File = [LOCAL_DIR 'filetoread.txt'];
FID_File = fopen(File,'r');
[words,var1,var2] = textscan(File,'%s %f %f','Delimiter',',');
fclose(FID_File);
I can't seem to figure out how to use a delimiter with textscan.
horchler is indeed correct. You first need to open up the file with fopen which provides a file ID / pointer to the actual file. You'd then use this with textscan. Also, you really only need one output variable because each "column" will be placed as a separate column in a cell array once you use textscan. You also need to specify the delimiter to be the , character because that's what is being used to separate between columns. This is done by using the Delimiter option in textscan and you specify the , character as the delimiter character. You'd then close the file after you're done using fclose.
As such, you just do this:
File = [LOCAL_DIR 'filetoread.txt'];
f = fopen(File, 'r');
C = textscan(f, '%s%f%f', 'Delimiter', ',');
fclose(f);
Take note that the formatting string has no spaces because the delimiter flag will take care of that work. Don't add any spaces. C will contain a cell array of columns. Now if you want to split up the columns into separate variables, just access the right cells:
names = C{1};
num1 = C{2};
num2 = C{3};
These are what the variables look like now by putting the text you provided in your post to a file called filetoread.txt:
>> names
names =
'a'
'aa'
'abb'
'ability'
'about'
>> num1
num1 =
142
3
5
3
2
>> num2
num2 =
5
0
0
0
0
Take note that names is a cell array of names, so accessing the right name is done by simply doing n = names{ii}; where ii is the name you want to access. You'd access the values in the other two variables using the normal indexing notation (i.e. n = num1(ii); or n = num2(ii);).
how do I insert a string into a csv file in matlab. i used this code to write some data and create my csv file:
and here is the output of the code:
I'm trying to insert some text in the first 2 columns before the numerical data..
thanks in advance :)
There are several approaches are possible here.
Let's take a look at some of them:
If you need to add string to your csv file.
For example, I create some csv file like your:
q = [1 2 3 4 5 6 7];
csvwrite('csvlist4.csv',q,2,0);
All troubles is to add some string to csv - it's because we need to combine numeric and text data. There are no good functions for it in Matlab except low levels:
c = 'some big text';
fid = fopen('csvlist4.csv','r+');
fprintf(fid,c);
How it works: the data in csv is an array. I put data in 3rd row, so first and second is an empty but they have ','. When you use fprintf it will replace this , with your text. So if text is too long it will overwrite your data.
How to avoid this?
Easiest way - is to do it with help of xlswrite function. For your example:
txt = cell(size(Q))
txt{1} = 'this is your text'
X = [txt; num2cell(Q)]
xlswrite('new.xlsx',X)
Result:
Important moment here: number of cell for text must be the same as your data. But I filled with the text only first cell in my example.
And the one more way: read csv file, modify it's data and write to csv:
csvwrite('csvlist4.csv',a,2,0);
m = csvread('csvlist4.csv');
fid = fopen('csvlist4.csv','w');
c = 'your text'
fprintf(fid, c); fprintf(fid, '\n');
fclose(fid);
dlmwrite('csvlist4.csv', m(3:end,:), '-append');
Of course you can use cell array instead c and so on and so on.
Hope it helps!
I have a cell array that has both strings and numbers. I want to load all the elements of the cell array. For the same I used the following method:
load(filename);
This command is loading only strings and excluding the columns that has numbers. Basically since my file is not .mat extension, it is treating it as ASCII file and loading only text.
I tried importdata(filename). But that gives me struct of 1*1. I need the elements to be imported into another cell array of same dimension.
Is there a way to load all the values?
load is used to import .mat-files with workspace variables. Since your data is not an actual .mat-file, you need to use a different method.
Let's assume you have the file filename with tab-delimited data:
str1 1
str2 2
str3 3
str4 4
To get a cell-array where the first column is a string (using %s) and the second a double (using %f), you can use textscan. Check out the result, maybe it's already what you're searching for.
filename = 'data';
F = fopen(filename, 'r');
data = textscan(F, '%s %f', 'Delimiter', '\t');
If not, you can create a cell-array CA where the first column is a string (using cellstr) and the second one is a double (using num2cell).
CA = cell(size(data{1},1),2);
CA(:,1) = cellstr(data{1});
CA(:,2) = num2cell(data{2});
Result:
CA =
'str1' [1]
'str2' [2]
'str3' [3]
'str4' [4]