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]
Related
I am trying to concatenate three lines (I want to leave the lines as is; 3 rows) from Shakespeare.txt file that shows:
To be,
or not to be:
that is the question.
My code right now is
fid = fopen('Shakespeare.txt')
while ~feof(fid)
a = fgets(fid);
b = fgets(fid);
c = fgets(fid);
end
fprintf('%s', strcat(a, b, c))
I'm supposed to use strcat and again, I want concatenated and leave them as three rows.
One method of keeping the rows separate is by storing the lines of the text file in a string array. Here a 1 by 3 string array is used. It may also be a good idea to use fgetl() which grabs each line of the text file at a time. Concantenating the outputs of fgetl() as strings may also be another option to ensure the they do not get stored as character (char) arrays. Also using the \n indicates to line break when printing the strings within the array String_Array.
fid = fopen('Shakespeare.txt');
while ~feof(fid)
String_Array(1) = string(fgetl(fid));
String_Array(2) = string(fgetl(fid));
String_Array(3) = string(fgetl(fid));
end
fprintf('%s\n', String_Array);
Ran using MATLAB R2019b
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 txt file that I want to read into Matlab. Data format is like below:
term2 2015-07-31-15_58_25_612 [0.9934343, 0.3423043, 0.2343433, 0.2342323]
term0 2015-07-31-15_58_25_620 [12]
term3 2015-07-31-15_58_25_625 [2.3333, 3.4444, 4.5555]
...
How can I read these data in the following way?
name = [term2 term0 term3] or namenum = [2 0 3]
time = [2015-07-31-15_58_25_612 2015-07-31-15_58_25_620 2015-07-31-15_58_25_625]
data = {[0.9934343, 0.3423043, 0.2343433, 0.2342323], [12], [2.3333, 3.4444, 4.5555]}
I tried to use textscan in this way 'term%d %s [%f, %f...]', but for the last data part I cannot specify the length because they are different. Then how can I read it? My Matlab version is R2012b.
Thanks a lot in advance if anyone could help!
There may be a way to do that in one single pass, but for me these kind of problems are easier to sort with a 2 pass approach.
Pass 1: Read all the columns with a constant format according to their type (string, integer, etc ...) and read the non constant part in a separate column which will be processed in second pass.
Pass 2: Process your irregular column according to its specificities.
In a case with your sample data, it looks like this:
%% // read file
fid = fopen('Test.txt','r') ;
M = textscan( fid , 'term%d %s %*c %[^]] %*[^\n]' ) ;
fclose(fid) ;
%% // dispatch data into variables
name = M{1,1} ;
time = M{1,2} ;
data = cellfun( #(s) textscan(s,'%f',Inf,'Delimiter',',') , M{1,3} ) ;
What happened:
The first textscan instruction reads the full file. In the format specifier:
term%d read the integer after the literal expression 'term'.
%s read a string representing the date.
%*c ignore one character (to ignore the character '[').
%[^]] read everything (as a string) until it finds the character ']'.
%*[^\n] ignore everything until the next newline ('\n') character. (to not capture the last ']'.
After that, the first 2 columns are easily dispatched into their own variable. The 3rd column of the result cell array M contains strings of different lengths containing different number of floating point number. We use cellfun in combination with another textscan to read the numbers in each cell and return a cell array containing double:
Bonus:
If you want your time to be a numeric value as well (instead of a string), use the following extension of the code:
%% // read file
fid = fopen('Test.txt','r') ;
M = textscan( fid , 'term%d %f-%f-%f-%f_%f_%f_%f %*c %[^]] %*[^\n]' ) ;
fclose(fid) ;
%% // dispatch data
name = M{1,1} ;
time_vec = cell2mat( M(1,2:7) ) ;
time_ms = M{1,8} ./ (24*3600*1000) ; %// take care of the millisecond separatly as they are not handled by "datenum"
time = datenum( time_vec ) + time_ms ;
data = cellfun( #(s) textscan(s,'%f',Inf,'Delimiter',',') , M{1,end} ) ;
This will give you an array time with a Matlab time serial number (often easier to use than strings). To show you the serial number still represent the right time:
>> datestr(time,'yyyy-mm-dd HH:MM:SS.FFF')
ans =
2015-07-31 15:58:25.612
2015-07-31 15:58:25.620
2015-07-31 15:58:25.625
For comlicated string parsing situations like such it is best to use regexp. In this case assuming you have the data in file data.txt the following code should do what you are looking for:
txt = fileread('data.txt')
tokens = regexp(txt,'term(\d+)\s(\S*)\s\[(.*)\]','tokens','dotexceptnewline')
% Convert namenum to numeric type
namenum = cellfun(#(x)str2double(x{1}),tokens)
% Get time stamps from the second row of all the tokens
time = cellfun(#(x)x{2},tokens,'UniformOutput',false);
% Split the numbers in the third column
data = cellfun(#(x)str2double(strsplit(x{3},',')),tokens,'UniformOutput',false)
I have a string in the following format :
fileName.jpg,10,20,10,10,...,12,14,True
Basically, I have a string with comma separated values. The first value is a string, then it follows an array of 100 values and lastly another string being true or false.
Is there a way or directly reading these values into 3 variable? Two strings and an array?
The array of values might contain n\a values which I want to treat as -1 or something similar or by using a cell array and having an empty cell for those? Can you recommend me something for this type of problem?
You can use textscan:
n = 100; % number of integers between filename and logical values
M = textscan(str, ['%s' repmat('%d',1, n) '%s'], 'delimiter', ',',...
'TreatAsEmpty', 'n\a', 'EmptyValue', -1, 'CollectOutput', true);
The result M is a cell array with the file name in the first cell, the 100 integer values in the second, and a string containing the logical value in the last cell.
You can use strsplit and extract the values from your String and store them in separate variables
Code Sample:
a = strsplit("fileName.jpg,10,20,10,10,...,12,14,True",",")
fileName = a(1)
flag = a(end)
data = a(2:end-1)