Is it possible to use checkcode or matlab.internal.codeanalyzer to parse a string of code, for example:
for i=1:100 a*b(i); end
without first putting that in a file and then calling checkcode or the internal parser.parse on that file. I want to check thousands of strings of code but dynamically without putting them in a file before each check. Ideally, I would like to be able to parse a string with the code in and have that parsed.
To be more clear incase there are other functions that could be useful, I actually want to parse a string and count the number of syntax errors, and find their location etc.
Seems mlintmex has a -text option which one can use to pass a string. It needs a string and a filename, however, it seems not to even use the filename, so not sure why. Furthermore, I can't figure out why, but when using -text there needs to be at least one parseable command. Therefore instead of calling
fid = fopen('tmp.m','wt');
fprintf(fid, '-mean[1:10)');
fclose(fid);
info = checkcode('tmp.m', '-fullpath');
one can use the following which has a great increase in performance:
% Get the errors with text mode
info = checkcode(['1;','-mean[1:10)'], 'tmp.m', '-fullpath', '-text');
% Reduce the columns to take in to account the '1;' in the checkcode call above.
for i=1:numel(info)
info(i).column = info(i).column - 2;
end
Using tic and toc in a loop for 1000 times, I get ~9 seconds for the file version and ~3-4 seconds for the -text version.
Related
I am creating a matlab application that is analyzing data on a daily basis.
The data is read in from an csv file using xlsread()
[num, weather, raw]=xlsread('weather.xlsx');
% weather.xlsx is a spreadsheet that holds a list of other files (csv) i
% want to process
for i = 1:length(weather)
fn = [char(weather(i)) '.csv'];
% now read in the weather file, get data from the local weather files
fnOpen = xlsread(fn);
% now process the file to save out the .mat file with the location name
% for example, one file is dallasTX, so I would like that file to be
% saved as dallasTx.mat
% the next is denverCO, and so denverCO.mat, and so on.
% but if I try...
fnSave=[char(weather(i)) '.mat'] ;
save(fnSave, fnOpen) % this doesn't work
% I will be doing quite a bit of processing of the data in another
% application that will open each individual .mat file
end
++++++++++++++
Sorry about not providing the full information.
The error I get when I do the above is:
Error using save
Argument must contain a string.
And Xiangru and Wolfie, the save(fnSave, 'fnOpen') works as you suggested it would. Now I have a dallasTX.mat file, and the variable name inside is fnOpen. I can work with this now.
Thanks for the quick response.
It would be helpful if you provide the error message when it doesn't work.
For this case, I think the problem is the syntax for save. You will need to do:
save(fnSave, 'fnOpen'); % note the quotes
Also, you may use weather{i} instead of char(weather(i)).
From the documentation, when using the command
save(filename, variables)
variables should be as described:
Names of variables to save, specified as one or more character vectors or strings. When using the command form of save, you do not need to enclose the input in single or double quotes. variables can be in one of the following forms.
This means you should use
save(fnSave, 'fnOpen');
Since you want to also use a file name stored in a variable, command syntax isn't ideal as you'd have to use eval. In this case the alternative option would be
eval(['save ', fnSave, ' fnOpen']);
If you had a fixed file name (for future reference), this would be simpler
save C:/User/Docs/MyFile.mat fnOpen
I have 1000 text files and want to read a number from each file.
format of text file as:
af;laskjdf;lkasjda123241234123
$sakdfja;lskfj12352135qadsfasfa
falskdfjqwr1351
##alskgja;lksjgklajs23523,
asdfa#####1217653asl123654fjaksj
asdkjf23s#q23asjfklj
asko3
I need to read the number ("1217653") behind "#####" in each txt file.
The number will follow the "#####" closely in all text file.
"#####" and the close following number just appear one time in each file.
clc
clear
MyFolderInfo = dir('yourpath/folder');
fidin = fopen(file_name,'r','n','utf-8');
while ~feof(fidin)
tline=fgetl(fidin);
disp(tline)
end
fclose(fidin);
It is not finish yet. I am stuck with the problem that it can not read after the space line.
This is another approach using the function regex. This will easily provide a more advanced way of reading files and does not require reading the full file in one go. The difference from the already given example is basically that I read the file line-by-line, but since the example use this approach I believe it is worth answering. This will return all occurences of "#####NUMBER"
function test()
h = fopen('myfile.txt');
str = fgetl(h);
k = 1;
while (isempty(str) | str ~= -1 ) % Empty line returns empty string and EOF returns -1
res{k} = regexp(str,'#####\d+','match');
k = k+1;
str = fgetl(h);
end
for k=1:length(res)
disp(res{k});
end
EDIT
Using the expression '#####(\d+)' and the argument 'tokens' instead of 'match' Will actually return the digits after the "#####" as a string. The intent with this post was also, apart from showing another way to read the file, to show how to use regexp with a simple example. Both alternatives can be used with suitable conversion.
Assuming the following:
All files are ASCII files.
The number you are looking to extract is directly following #####.
The number you are looking for is a natural number.
##### followed by a number only occurs once per file.
You can use this code snippet inside a for loop to extract each number:
regx='#####(\d+)';
str=fileread(fileName);
num=str2double(regexp(str,regx,'tokens','once'));
Example of for loop
This code will iterate through ALL files in yourpath/folder and save the numbers into num.
regx='#####(\d+)'; % Create regex
folderDir='yourpath/folder';
files=cellstr(ls(folderDir)); % Find all files in folderDir
files=files(3:end); % remove . and ..
num=zeros(1,length(files)); % Pre allocate
for i=1:length(files) % Iterate through files
str=fileread(fullfile(folderDir,files{i})); % Extract str from file
num(i)=str2double(regexp(str,regx,'tokens','once')); % extract number using regex
end
If you want to extract more ''advanced'' numbers e.g. Integers or Real numbers, or handle several occurrences of #####NUMBER in a file you will need to update your question with a better representation of your text files.
I have an application that translates the .csv files I currently have into the correct format I need. But, the files I that I do have seem to have '"' double quotes around them, as seen in this image, which will not work with the program. As a result, I'm using this command to remove them:
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = strrep(current{m,n}, '"', '');
end
end
I'm not entirely sure that this works though, as it spits this back at me as it runs:
Warning: Inputs must be character arrays or cell arrays of strings.
When I open the file in matlab, it seems to only have the single quotes around it, which is normal for any other file. However, when I open it in notepad++, it seems to have '"' double quotes around everything. Is there a way to remove these double quotes in any other way? My code doesn't seem to do anything as seen here:
After using xlswrite to write the replacement cell-array to a .csv file, one appears corrupted. Any idea why?
So, my questions are:
Is there any way to remove the quotes in a more efficient manner or without rewriting to a csv?
and
What exactly is causing the corruption in the xlswrite function? The variable replacement seems perfectly normal.
Thanks in advance!
Regarding the "corrupted" file. That's not a corrupted file, that's an xls file (not xlsx). You could verify this opening the text file in a hex editor to compare the signature. This happens when you chose no file extension or ask excel to write a file which can't be encoded into csv. I assume it's some character which causes the problems, try to isolate the critical line writing only parts of the cell.
Regarding your warning, not having the actual input I could only guess what's wrong. Again, I can only give some advices to debug the problem yourself. Run this code:
lastwarn('')
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = strrep(current{m,n}, '"', '');
if ~isempty(lastwarn)
keyboard
lastwarn('')
end
end
end
This will launch the debugger when a warning is raised, allowing you to check the content of current{m,n}
It is mentionned in the documentation of strrep that :
The strrep function does not find empty strings for replacement. That is, when origStr and oldSubstr both contain the empty string (''), strrep does not replace '' with the contents of newSubstr.
You can use this user function substr like this :
for m = 1:currentsize(1)
for n = 1:currentsize(2)
replacement{m,n} = substr(current{m,n}, 2, -1);
end
end
Please use xlswrite function like this :
[status,message] = xlswrite(___)
and check the status if it is zero, that means the function did not succeed and an error message is generated in message as string.
I am trying to import all double from a txt file, which has this form
#25x1 string
#9999x2 double
.
.
.
#(repeat ten times)
However, when I am trying to use import Wizard, only the first
25x1 string
9999x2 double.
was successfully loaded, the other 9 were simply ignored
How may I import all the data? (Does importdata has a maximum length or something?)
Thanks
It's nothing to do with maximum length, importdata is just not set up for the sort of data file you describe. From the help 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:
Column headers or file description text at the top of the file, above
the numeric data. Row headers to the left of the numeric data.
So what is happening is that the first section of your file, which does match the format importdata expects, is being read, and the rest ignored. Instead of importdata, you'll need to use textscan, in particular, this style:
C = textscan(fileID,formatSpec,N)
fileID is returned from fopen. formatspec tells textscan what to expect, and N how many times to repeat it. As long as fileID remains open, repeated calls to textscan continue to read the file from wherever the last read action stopped - rather than going back to the start of the file. So we can do this:
fileID = fopen('myfile.txt');
repeats = 10;
for n = 1:repeats
% read one string, 25 times
C{n,1} = textscan(fileID,'%s',25);
% read two floats, 9999 times
C{n,2} = textscan(fileID,'%f %f',9999);
end
You can then extract your numerical data out of the cell array (if you need it in one block you may want to try using 'CollectOutput',1 as an option).
I have a MATLAB program that graphs some things and then outputs the graph to a file. If I run this program several times in the same directory, the file gets overwritten each time. How can I make it so the filename it outputs to changes...
I currently have this:
print -depsc myfigure
I have strings, rate and name, that I want to use, but can't get anything to work. If I can't use my strings, something random would be fine as well. Any way to do this?
Many thanks!
Name it with the current date and time:
print('-depsc2', ['prefix_' datestr(now, 30)])
run right now in PST, this creates a file called prefix_20100220T200733.eps. You can obviously change the prefix and/or the date format.
You can add current time to your file name. For example:
m=magic(10);
fh=figure, surf(m);
currenttime= datestr(now,'MMSSFFF');
print(['-f',num2str(fh)],'-depsc',['outputFileName_',currenttime,'.eps']);
This code checks if file exists, and if yes, adds a counter to its name.
filename = 'myfigure';
if exist([filename '.eps'],'file')
k=1;
while exist([filename '_' num2str(k) '.eps'], 'file')
k=k+1;
end
filename = [filename '_' num2str(k)]);
end
print('-depsc', filename);
Its simple. worked for me.
currenttime= datestr(now,'dd-mm-yy_HH:MM')
filename= ['graph' currenttime '.jpg']
print('-dpdf',filename)
Or any other file format you want to export. check print help.