I import text in matlab using importdata
A = importdata(logFile, '\t', 1);
this works fine, unless the "SUB" char is at the end of the file.
In this case I get the error
Error in
matlab.graphics.internal.figfile.FigFile/read>#(hObject,eventdata)uiProjekt('menuEvalAllData_Callback',hObject,eventdata,guidata(hObject))
Caused by:
Error using vertcat
Dimensions of matrices being
concatenated are not
consistent.
My question is: how can I work around this error?
The simplest idea would be to remove the char from the file before. But how would I remove a single char from a large text file efficiently?
You can use strrep to replace the SUB char. strrep is pretty efficient and should be fast even with large files.
The decimal value of the SUB char in ASCII is 26.
Here's an example code that removes the SUB char from an input file input.txt:
% Open files:
inputID = fopen('input.txt','r');
outputID = fopen('output.txt','w');
file_data=fread(inputID,'*char')'; % Read all data from input file
file_data_fixed = strrep(file_data,char(26),''); % Find and replace the SUB char with blank
fprintf(outputID,'%s',file_data_fixed); % Print all data (without SUB) to output file
% Close files:
fclose(inputID);
fclose(outputID);
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 this code and want to write an array in a tab delimited txt file :
fid = fopen('oo.txt', 'wt+');
for x = 1 :length(s)
fprintf(fid, '%s\t\n', s(x)(1)) ;
end;
fclose(fid);
but I receive this error :
Error: ()-indexing must appear last in an index expression.
how should i call s(x)(1)? s is an array
s <2196017x1 cell>
when I use this code I get no error but return me some characters not words.
fprintf(fid, '%s\t\n', ( s{x}{1})) ;
With MATLAB, you cannot immediately index into the result of a function using () without first assigning it to a temporary variable (Octave does allow this though). This is due to some of the ambiguities that happen when you allow this.
tmp = s(x);
fprintf(fid, '%s\t\n', tmp(1)) ;
There are some ways around this but they aren't pretty
It is unclear what exactly your data structure is, but it looks like s is a cell so you should really be using {} indexing to access it's contents
fprintf(fid, '%s\t\n', s{x});
Update
If you're trying to read individual words in from your input file and then write those out to a tab-delimited file, I'd probably do something like the following:
fid = fopen('input.txt', 'r');
contents = fread(fid, '*char')';
fclose(fid)
% Break a string into words and yield a cell array of strings
words = regexp(contents, '\s+', 'split');
% Write these out to a file separated by tabs
fout = fopen('output.tsv', 'w');
fprintf(fout, '%s\t', words{:});
fclose(fout)
Dear All (with many thanks in advance),
The following script has trouble reading (and therefore writing) the %s character in the file 'master.py'.
I get that matlab thinks the %s is an escape character, so perhaps an option is to modify the terminator, but I have found this difficult.
(EDIT: Forgot to mention the file master.py is not in my control, so I can't modify the file to %%s for example).
%matlab script
%===============
fileID = fopen('script.py','w');
yMax=5;
fprintf(fileID,'yOverallDim = %d\n', -1*yMax);
%READ IN "master.py" for rest of script
fileID2 = fopen('master.py','r');
currentLine = fgets(fileID2);
while ischar(currentLine)
fprintf(fileID,currentLine);
currentLine = fgets(fileID2);
end
fclose(fileID);
fclose(fileID2);
The file 'master.py' looks like this (and the problem is on line 6 'setName ="Set-%s"%(i+1)':
i=0
for yPos in range (0,yOverallDim,yVoxelSize):
yCoordinate=yPos+(yVoxelSize/2) #
for xPos in range (0,xOverallDim,xVoxelSize):
xCoordinate=xPos+(xVoxelSize/2)
setName ="Set-%s"%(i+1)
p = mdb.models['Model-1'].parts['Part-1']
# p = mdb.models['Model-1'].parts['Part-2']
c = p.cells
cells = c.findAt(((xCoordinate, yCoordinate, 10.0), ))
region = p.Set(cells=cells, name=setName)
p.SectionAssignment(region=region, sectionName='Section-1', offset=0.0, offsetType=MIDDLE_SURFACE, offsetField='', thicknessAssignment=FROM_SECTION)
i+=1
In the documentation of fprintf you'll find this:
fprintf(fileID,formatSpec,A1,...,An) applies the formatSpec to all elements of arrays A1,...An in column order, and writes the data to a text file.
So in your function fprintf uses currentLine as format specification, resulting in an unexpected output for line 6. Correct application of fprintf by providing a formatSpec, fixes this issue and doesn't require any replace operations:
fprintf(fileID, '%s', currentLine);
Your script has no trouble reading the % characters correctly. The "problem" is with fprintf(). This function correctly interpretes the percent signs in the string as formatting characters. Therefore, I think you have to manually escape every single % character in your currentLine string:
currentLine = strrep(currentLine, '%', '%%');
At least, it worked when I checked it on your example data.
Thanks applesoup for identifying my fundamental oversight - the problem is in the fprintf - not in the file read
Thanks serial for enhancing the fprintf
I want to read the data of a file with size about 60 MB into matlab in some variables, but I get errors. This is my code:
clear all ;
clc ;
% Reading Input File
Dataz = importdata('leak0.lis');
%Dataz = load('leak0.lis');
for k = 1:1370
foundPosition = 1 ;
for i=1:size(Dataz,1)
strp = sprintf('I%dz=',k);
fprintf(strp);
findValue = strfind(Dataz{i}, strp) ;
if ~isempty(findValue)
eval_param = strp + '(foundPosition) = sscanf(Dataz{i},''%*c%*c%*f%*c%*c%f'') ;';
disp(eval_param);
% str(foundPosition) = sscanf(Dataz{i},'%*c%*c%*f%*c%*c%f') ;
eval(eval_param);
foundPosition = foundPosition + 1 ;
end
end
end
When I debugged it, I found out that the dataz is empty & so it doesn't proceed to next lines. I replace it with fopen, load & etc, but it didn't work.
From the Matlab help files, import data is likely failing because it doesn't understand your file format.
From the help files
Name and extension of the file to import, specified as a string. If importdata recognizes the file extension, it calls the MATLAB helper function designed to import the associated file format (such as load for MAT-files or xlsread for spreadsheets). Otherwise, importdata interprets the file as a delimited ASCII file.
For ASCII files and spreadsheets, importdata expects to find numeric
data in a rectangular form (that is, like a matrix). Text headers can
appear above or to the left of the numeric data, as follows:
Assuming that your .lis files actually have delimited text.
You should adjust the delimiter in the importdata call so that Matlab can understand your file.
filename = 'myfile01.txt';
delimiterIn = ' ';
headerlinesIn = 1;
A = importdata(filename,delimiterIn,headerlinesIn);
Loading a well formatted and delimited text file in Matlab is relatively simple, but I struggle with a text file that I have to read in. Sadly I can not change the structure of the source file, so I have to deal with what I have.
The basic file structure is:
123 180 (two integers, white space delimited)
1.5674e-8
.
.
(floating point numbers in column 1, column 2 empty)
.
.
100 4501 (another two integers)
5.3456e-4 (followed by even more floating point numbers)
.
.
.
.
45 String (A integer in column 1, string in column 2)
.
.
.
A simple
[data1,data2]=textread('filename.txt','%f %s', ...
'emptyvalue', NaN)
Does not work.
How can I properly filter the input data? All examples I found online and in the Matlab help so far deal with well structured data, so I am a bit lost at where to start.
As I have to read a whole bunch of those files >100 I rather not iterate trough every single line in every file. I hope there is a much faster approach.
EDIT:
I made a sample file available here: test.txt (google drive)
I've looked at the text file you supplied and tried to draw a few general conclusions -
When there are two integers on a line, the second integer corresponds to the number of rows following.
You always have (two integers (A, B) followed by "B" floats), repeated twice.
After that you have some free-form text (or at least, I couldn't deduce anything useful about the format after that).
This is a messy format so I doubt there are going to be any nice solutions. Some useful general principles are:
Use fgetl when you need to read a single line (it reads up to the next newline character)
Use textscan when it's possible to read multiple lines at once - it is much faster than reading a line at a time. It has many options for how to parse, which it is worth getting to know (I recommend typing doc textscan and reading the entire thing).
If in doubt, just read the lines in as strings and then analyse them in MATLAB.
With that in mine, here is a simple parser for your files. It will probably need some modifications as you are able to infer more about the structure of the files, but it is reasonably fast on the ~700 line test file you gave.
I've just given the variables dummy names like "a", "b", "floats" etc. You should change them to something more specific to your needs.
function output = readTestFile(filename)
fid = fopen(filename, 'r');
% Read the first line
line = '';
while isempty(line)
line = fgetl(fid);
end
nums = textscan(line, '%d %d', 'CollectOutput', 1);
a = nums{1}(1);
b = nums{1}(2);
% Read 'b' of the next lines:
contents = textscan(fid, '%f', b);
floats1 = contents{1};
% Read the next line:
line = '';
while isempty(line)
line = fgetl(fid);
end
nums = textscan(line, '%d %d', 'CollectOutput', 1);
c = nums{1}(1);
d = nums{1}(2);
% Read 'd' of the next lines:
contents = textscan(fid, '%f', d);
floats2 = contents{1};
% Read the rest:
rest = textscan(fid, '%s', 'Delimiter', '\n');
output.a = a;
output.b = b;
output.c = c;
output.d = d;
output.floats1 = floats1;
output.floats2 = floats2;
output.rest = rest{1};
end
You can read in the file line by line using the lower-level functions, then parse each line manually.
You open the file handle like in C
fid = fopen(filename);
Then you can read a line using fgetl
line = fgetl(fid);
String tokenize it on spaces is probably the best first pass, storing each piece in a cell array (because a matrix doesn't support ragged arrays)
colnum = 1;
while ~isempty(rem)
[token, rem] = strtok(rem, ' ');
entries{linenum, colnum} = token;
colnum = colnum + 1;
end
then you can wrap all of that inside another while loop to iterate over the lines
linenum = 1;
while ~feof(fid)
% getl, strtok, index bookkeeping as above
end
It's up to you whether it's best to parse the file as you read it or read it into a cell array first and then go over it afterwards.
Your cell entries are all going to be strings (char arrays), so you will need to use str2num to convert them to numbers. It does a good job of working out the format so that might be all you need.