I have file names go on 2.txt 4.txt 8.txt 12.txt 14.txt. And each file structure looks like
I want to read each designated file and do some calculations with the designated columns for instance, after calling 2.txt file I want to calculate
column(A)+column(I)
The questions
How can I call the certain file with their name
How can I do calculations with this file columns
Here is my code
function[t]=ad(x)
folderName='C:\Users\zeldagrey6\Desktop\AD';
fileinfo=dir([folderName filesep '**/*.txt'] );
filename={fileinfo.name};
fullFileName=[folderName filesep filename{x}];
d=readtable(fullFileName, 'ReadVariableNames', true);
t=d.A+d.I;
end
The problems of the code
When I put ad(2) into array i call 4.txt instead of 2.txt. I guess it does not care the names of the text just read them according to their sequence
Is there any way to assign with each column like var1,var2 and do some
calculations with var1+var2 instead of d.A+d.I
yes, you can refer to table contents with curly brackets like this:
A = (30.1:0.1:30.5)';
I = (324:328)';
Angle = (35:5:55)';
FWHM = (0.2:0.05:0.4)';
d = table(A,I,Angle,FWHM);
t1 = d.A + d.I;
t2 = d{:,1} + d{:,2};
See that t1 and t2 are equal
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 using this line to read all Images in a file:
imagefiles = dir('Images\*.jpg');
Suppose I have the names: a1.jpg,a11.jpg,b13.JPG,b5.JPG,c1.jpg.
How do I group together all images with no more than 2 different characters (the number) in their name. for the given example group together all a and all b and atheired group for c.
By grouping I mean form some kind of data structure or order that will enable me to access each group separately for later processing?
I am assuming the file type is always 'jpg' and the numbers will always be smaller then 100 and positive. I am assuming a not case sensitive code regarding file type, that is jpg and JPG may appear (I don't know regular expression but will be happy to learn from a good link as well)
You could capture the initial non-number part of the file name using regexp, group them with unique and put them in a struct.
% Some test data
files = {'a11','a1','b2','a32','ca3','b45','c1','ca2'};
files = strcat(files, '.jpg');
% Capture and group
tag = regexp(files,'^\D+','match','once');
[unTag, ~, unIdx] = unique(tag);
for idx = 1:length(unTag)
fileGroups.(unTag{idx}) = files(unIdx == idx);
end
% The result
>> fileGroups =
a: {'a11.jpg' 'a1.jpg' 'a32.jpg'}
b: {'b2.jpg' 'b45.jpg'}
c: {'c1.jpg'}
ca: {'ca3.jpg' 'ca2.jpg'}
Depending on how your filenames you might have to update to a more detailed regular expression. You could use \D+(?=\d+\.(JPG|jpg)) to caputure a non-digit char before some number and the .jpg extension.
So if your file names are something like:
>> files
'dummyStr_a11.jpg'
'dummyStr_a1.jpg'
'dummyStr_b2.jpg'
'dummyStr_a32.jpg'
'dummyStr_ca3.jpg'
'dummyStr_b45.jpg'
'dummyStr_c1.jpg'
'dummyStr_ca2.jpg'
Capture with something like
tag = regexp(files,'[a-z]+(?=\d+\.(JPG|jpg))','match','once');
>> tag =
'a' 'a' 'b' 'a' 'ca' 'b' 'c' 'ca'
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);).
I have a large text file (~3500 lines) which contains output data from an instrument. This consists of repeated entries from different measurements which are all formatted as follows:
* LogFrame Start *
variablename1: value
variablename2: value
...
variablename35: value
* LogFrame End *
Each logframe contains 35 variables. From these I would like to extract two, 'VName' and 'EMGMARKER' and put the associated values in columns in a matlab array, (i.e. the array should be (VName,EMGMARKER) which I can then associate with data from another output file which I already have in a matlab array. I have no idea where to start with this in order to extract the variables from this file, so hence my searches on the internet so far have been unsuccessful. Any advice on this would be much appreciated.
You could use textscan:
C = textscan(file_id,'%s %f');
Then you extract the variables of interest like this:
VName_indices = strcmp(C{1},'VName:');
VName = C{2}(VName_indices);
If the variable names, so 'VName' and 'EMGMARKER' , are always the same you can just read through the file and search for lines containing them and extract data from there. I don't know what values they contain so you might have to use cells instead of arrays when extracting them.
fileID = fopen([target_path fname]); % open .txt file
% read the first line of the specified .txt file
current_line = fgetl(fileID);
counter = 1;
% go through the whole file
while(ischar(current_line))
if ~isempty(strfind(current_line, VName))
% now you find the location of the white space delimiter between name and value
d_loc = strfind(current_line,char(9));% if it's tab separated - so \t
d_loc = strfind(current_line,' ');% if it's a simple white space
variable_name{counter} = strtok(current_line);% strtok returns everything up until the first white space
variable_value{counter} = str2double(strtok(current_line(d_loc(1):end)));% returns everything form first to second white space and converts it into a double
end
% same block for EMGMARKER
counter = counter+1;
current_line = fgetl(fileID);% next line
end
You do the same for EMGMARKER and you have cells containing the data you need.
I have an array which I read into Matlab with importdata. It has 5 header lines
file = 'aoao.csv';
s = importdata(file,',', 5);
Matlab automatically treats the last line as the column header. I can then call up the column number that I want with
s.data(:,n); %n is desired column number
I want to be able to load up many similar files at once, and then call up the columns in the different files which have the same column header name (which are not necessarily the same column number). I want to be able to write and export all of these columns together into a new matrix, preferably with each column labelled with its file name,
what should I do?
samp = 'len-c.mp3'; %# define desired sample/column header name
file = dir('*.csv');
have the directory ready in main screen current folder. This creates a detailed description of file,
for i=1:length(file)
set(i) = importdata(file(i).name,',', 5);
end
this imports the data from each of the files (comma delimited, 5 header lines) and transports it to a cell array called 'set'
for k = 1:14;
for i=1:length(set(k).colheaders)
TF = strcmp(set(k).colheaders(i),samp); %compares strings for match
if TF == 1; %if match is true
group(:,k) = set(k).data(:,i); %save matching column# to 'group'
end
end
end
this retrieves the data from the named colheader within each file