I don't know if Matlab can do this, but I want to store some strings in a 4×3 matrix, each element in the matrix is a string.
test_string_01 test_string_02 test_string_03
test_string_04 test_string_05 test_string_06
test_string_07 test_string_08 test_string_09
test_string_10 test_string_11 test_string_12
Then, I want to write this matrix into a plain text file, either comma or space delimited.
test_string_01,test_string_02,test_string_03
test_string_04,test_string_05,test_string_06
test_string_07,test_string_08,test_string_09
test_string_10,test_string_11,test_string_12
Seems like matrix data type is not capable of storing strings. I looked at cell. I tried to use dlmwrite() or csvwrite(), but both of them only accept matrices. I also tried cell2mat() first, but in that way all letters in the strings are comma seperated, like
t,e,s,t,_,s,t,r,i,n,g,_,0,1,t,e,s,t,_,s,t,r,i,n,g,_,0,2,t,e,s,t,_,s,t,r,i,n,g,_,0,3
So is there any way to achieve this?
It is possible to shorten yuk's solution a bit.
strings = {
'test_string_01','test_string_02','test_string_03'
'test_string_04','test_string_05','test_string_06'
'test_string_07','test_string_08','test_string_09'
'test_string_10','test_string_11','test_string_12'};
fid = fopen('output.txt','w');
fmtString = [repmat('%s\t',1,size(strings,2)-1),'%s\n'];
fprintf(fid,fmtString,strings{:});
fclose(fid);
Cell array is the way to store strings.
I agree it's a pain to save strings into a text file, but you can do it with this code:
strings = {
'test_string_01','test_string_02','test_string_03'
'test_string_04','test_string_05','test_string_06'
'test_string_07','test_string_08','test_string_09'
'test_string_10','test_string_11','test_string_12'};
fid = fopen('output.txt','w');
for row = 1:size(strings,1)
fprintf(fid, repmat('%s\t',1,size(strings,2)-1), strings{row,1:end-1});
fprintf(fid, '%s\n', strings{row,end});
end
fclose(fid);
Substitute \t with , to get csv file.
You can also store cell array of strings into Excel file with XLSWRITE (requires COM interface, so it's on Windows only):
xlswrite('output.xls',strings)
In most cases you can use the delimiter ' ' and get Matlab to save a string into file with dlmwrite.
For example,
output=('my_first_String');
dlmwrite('myfile.txt',output,'delimiter','')
will save a file named myfile.txt containing my_first_String.
Related
I want to write a function that loads a text file and plots its content with time. I have 20 text files so I want to be able to choose from them.
My current not working code:
TextFile is a generic variable
text123.txt is the actual name of one of the files i want to load
function []= PlotText(TextFile)
text(1,:)=load('text123.txt') ;
t=0:10;
plot(t,text)
end
I appreciate any help!!
use importdata instead of load with appropriate delimiter. I assume you used Tab.
filename = 'num.txt';
delimiterIn = '\t';
text = importdata(filename,delimiterIn)
t=1:10;
plot(t,text);
Firstly, you can also use dlmread if your file contains only numeric data separated by the same symbol (called a delimiter) such as a comma (,), semicolon (;), space ( ), or tab ( ). This would look like:
function []= PlotText(TextFile)
text(1,:)=dlmread('text123.txt');
t=0:10;
plot(t,text)
end
Keep in mind that your code is written in a way that expects the contents of text123.txt to have 11 values in a single row. Also, if you are using multiple files, then I suggest having the file name be another input to the function:
function []= PlotText(TextFile,filename)
text(1,:)=load(filename) ;
t=0:10;
plot(t,text)
end
I would like to split pathstr into separate parts how can I do this? See example below.
PS: I'm using octave 3.8.1
dpath='tmp/h1/cli/pls/03sox_a_Fs_1000/'
[pathstr,name,ext] = fileparts(dpath)
>>>pathstr = tmp/h1/cli/pls/03sox_a_Fs_1000
If all I want is 03sox_a_Fs_1000 or pls
How can I do this?
Please note the filenames will change and could be of different lengths.
You can use strsplit (here using Matlab) to split your string (believe it or not!) using the delimiter /:
pathstr = 'tmp/h1/cli/pls/03sox_a_Fs_1000'
[Name,~] = strsplit(pathstr,'/')
Now Name looks like this:
Name =
'tmp' 'h1' 'cli' 'pls' '03sox_a_Fs_1000'
So you can select the last element using the end keyword and curly braces since the output of strsplit is a cell array:
Name = Name{end}
or end-1 to retrieve pls.
This applies to names of any length or format, as long as they are separated by /.
This problem is bugging me and the solution is probably obvious but i cant find it.
I have a bunch of data files which i want to load:
ex_file-1.txt, ex_file-2.txt, ..., ex_file-10.txt
To get their filenames i use:
files = dir('ex_file-*.txt');
This returns a struct with fields name, type, etc. The field name returns:
ex_file-1.txt, ex_file-10.txt, ex_file-2.txt, ..., ex_file-9.txt
I would like to sort this such that ex_file-10.txt is the last file rather than the second.
I have attempted to concatenate, convert to cells and sort but none seem to give what i need. I know that the most obvious solution would be to rename all file names so all strings have the same length but i'd prefer not to do that.
This could be one approach -
%// Input cell array of filenames
names = {'ex_file-1.txt', 'ex_file-10.txt', 'ex_file-2.txt', 'ex_file-3.txt', ...
'ex_file-4.txt', 'ex_file-5.txt'}
%// Reomove the starting common "ex_file" string
stripped_names = strrep(names,'ex_file-','')
%// Remove the ending extension part
stripped_names = strrep(stripped_names,'.txt','')
%// Convert to doubles and then get the sorted indices
[~,idx] = sort(str2double(stripped_names))
%// Use sorted indices to rearrange names array, for the final output
names_out = names(idx)
Code run -
>> names
names =
'ex_file-1.txt' 'ex_file-10.txt' 'ex_file-2.txt' 'ex_file-3.txt' 'ex_file-4.txt' 'ex_file-5.txt'
>> names_out
names_out =
'ex_file-1.txt' 'ex_file-2.txt' 'ex_file-3.txt' 'ex_file-4.txt' 'ex_file-5.txt' 'ex_file-10.txt'
This can be done using regular expressions. The numeric part of file name is detected as a subsequence of numeric characters right before the .txt part.
files = dir('ex_file-*.txt'); %// get file struct array
names = {files.name}; %// get file names. Cell array of strings
numbers = regexp(names, '\d+(?=\.txt)', 'match'); %// strings with numeric part of name
numbers = str2double([numbers{:}]); %// convert from strings to numbers
[~, ind] = sort(numbers); %// sort those numbers
names_sorted = names(ind); %// apply that order to file names
Here is a alternative which does not require any details about the file name. Primary sorting rule shortest first, secondary lexicographic:
%secondary sorting
list=sort(list);
%primary sorting by length
[a,b]=sort(cellfun(#numel,list)):
list=list(b);
I am creating a program which opens an image, and uses the MATLAB ginput command to store x and y coordinates, which are operated on in the loop to fulfill requirements of an if statement and output a number or string corresponding to the region clicked during the ginput session. At the same time, I am using the input command to input a string from the command window relating to these numbers. The ginput session is placed in a while loop so a click in a specific area will end the input session. For each session (while loop), only one or two inputs from the command window are needed. Finally, I am trying to store all the data in a csv or txt file, but I would like it to be tabulated so it is easy to read, i.e. rows and columns with headers. I am including some sample code. My questions are: 1, how can an input of x and y coordinates be translated to a string? It is simple to do this for a number, but I cannot get it to work with a string. 2, any help on printing the strings and number to a tabulated text or cdv file would be appreciated.
Command line input:
prompt='Batter:';
Batter=input(prompt,'s');
While Loop:
count=1;
flag=0;
while(flag==0)
[x,y]= ginput(1);
if (y>539)
flag=1;
end
if x<594 && x>150 && y<539 && y>104
%it's in the square
X=x;
Y=y;
end
if x<524 && x>207 && y<480 && y>163
result='strike'
else
result='ball'
end
[x,y]= ginput(1);
pitch=0;
if x<136 && x>13
%its' pitch column
if y<539
pitch=6;
end
if y<465
pitch=5;
end
if y<390
pitch=4;
end
if y<319
pitch=3;
end
if y<249
pitch=2;
end
if y<175
pitch=1;
end
end
if pitch==0
else
plot(X,Y,'o','MarkerFaceColor',colors(pitch),'MarkerSize',25);
text(X,Y,mat2str(count));
end
count=count+1
M(count,:)=[X,Y,pitch];
end
For the above series of if statements, I would prefer a string output rather than the numbers 1-6 if the condition is satisfied.
The fprintf function is used to print to a file, but I have issues combining the strings and numbers using it:
fileID = fopen('pitches.csv','w');
fid = fopen('gamedata.txt','w');
fmtString = [repmat('%s\t',1,size(Batter,2)-1),'%s\n'];
fprintf(fid,fmtString,Batter,result);
fclose(fid);
for i=1:length(M)
fprintf(fileID,'%6.2f %6.2f %d\n',M(i,1),M(i,2),M(i,3));
end
fclose(fileID);
I have tried adding the string handles to the fprintf command along with the columns of M, but get errors. I either need to store them in an array (How?) and print all the array columns to the file, or use some other method. I also tried a version of the writetable method:
writetable(T,'tabledata2.txt','Delimiter','\t','WriteRowNames',true)
but I can't get everything to work right. Thanks very much for any help.
Let's tackle your questions one at a time:
1, how can an input of x and y coordinates be translated to a string?
You can use the sprintf command in MATLAB. This takes exactly the same syntax as fprintf, but the output of this function will give you a string / character array of whatever you desire.
2, any help on printing the strings and number to a tabulated text or cdv file would be appreciated.
You can still use fprintf but you can specify a matrix as the input. As such, you can do this:
fprintf(fileID,'%6.2f %6.2f %d\n', M.');
This will write the entire matrix to file. However, care must be taken here because MATLAB writes to files in column major format. This means that it will traverse along the rows before going to the next column. If you want to write data row by row, you will need to transpose the matrix first so that when you are traversing down the rows, it will basically do what you want. You will need to keep this in mind before you start trying to write strings to an file. What I would recommend is that you place each string in a cell array, then loop through each element in the cell array and write each string individually line by line.
Hopefully this helps push you in the right direction. Reply back to me in a comment and we can keep talking if you need more help.
I would like to read an excel file (xlsread) but I don't want to put manually the string every time but instead I want to xlsread the name of the file that is contained in an array.
For example, my array B is:
B =
'john.xlsx'
'mais.xlsx'
'car.xlsx'
Then I would like to read the excel WITH THE NAME that is inside the first element, that means: "john.xlsx"
How can I do this?
data = xlsread(B{1});
Or, if you want to read all of them:
for i=1:length(B)
data(i).nums = xlsread(B{i});
end
Assuming, of course, your B is a cell array. If it's not, it can't exist the way you described it. If all strings have the same length (then it would be possible) or padding with spaces, you can split the char array into a cell array using
B = mat2cell(B,ones(size(B,1),1),size(B,2));
Strings of different lengths would have to be inside a cell array, which you can access elements via the curly brackets {}. So, you can call xlsread on the first element this way:
names{1} = 'john.xlsx';
names{2} = 'mais.xlsx';
names{3} = 'car.xlsx';
num = xlsread(names{1});