Reading numerical data from text fles with string

Dear all,

I will really appreciate f you help me out in this regards. I am using follwing code to read multiple text files and genrating a data based on specific columns. I now wanted to read the numeric values from line 10 and 11 and place them in first and column of data and repeat them for all the values of a specific cell array. Based on new cell array, the values should change till the end of that array and so on.....

clear;

D = 'T:\Intelli_test\New\files';

S = dir(fullfile(D, '*.txt'));

N = length(S);

% A = cell(N,1);

fmt = '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f';

for k = 1:N

fid = fopen(fullfile(D,S(k).name), 'r');

A(k)= textscan(fid, fmt, 'Delimiter', '\t', ...

'headerlines', 33, ...

'CollectOutput', 1);

fid=fclose(fid);

M = vertcat(A{:});

out = M(:,[9,11]);

data=out;

end

i am now trying to add a loop like this to get the values but i am getting nothing

for k = 1:N

fid = fopen(fullfile(D,S(k).name), 'r');

linenum = 10;

h(k)= textscan(fid,'%f',1,'delimiter','\n', 'headerlines',linenum-1);

fid=fclose(fid);

end

[Stephen23]

Note that this line

M = vertcat(A{:});

and the ones that follow it until the end of the loop should go after the loop.

There is no point in calling them inside the loop like that.

Answer 1

[Mathieu NOE]

hello

my suggestion for the second part of your code , assuming you specify the lines to be read :

n_lines = [10 11]; % define lines to read
for k = 1:N
    fid = fopen(fullfile(D,S(k).name), 'r'); % open file
    result = cell(1,numel(n_lines));
    for n = 1:numel(n_lines)
        result(n) = textscan(fid, '%s', 1, 'Headerlines', n_lines(n)-1, 'Delimiter' ,'');
        frewind(fid) % set file position back to the start
    end
    result = [result{:}]; % unbox from cells
    fclose(fid); % close file
end

[fadzhi]

Many thanks for your answer but i am not being able to loop over all text files. Further, i was only interested in numeric values of temperature and strainrate and not the complete string'Temperature: 250 °C': Do you have any suggestion how i can parse the string and only obtain numeric values

[Mathieu NOE]

oops sorry, I'll try to fix that tomorrow

[Mathieu NOE]

so , now i hope it works better :

see the results in array result

n_lines = [10 11]; % define lines to read
result = zeros(N,numel(n_lines));

for k = 1:N
    fid = fopen(fullfile(D,S(k).name), 'r'); % open file
    for n = 1:numel(n_lines)
        str = textscan(fid, '%s', 1, 'Headerlines', n_lines(n)-1, 'Delimiter' ,'\n'); % change %s (string) to %f to get first numerical value (does not work ??)
        tmp = regexp(char(str{1}),'-?\d+\.?\d*|-?\d*\.?\d+','match'); % extract numerical content of string
        result(k,n) = str2num(tmp{:});
        frewind(fid) % set file position back to the start
    end
    fclose(fid); % close file
end

[fadzhi]

Once again many thanks...........

Giving me an error like

Not enough input arguments

Error in Str2num

if ~ischar(s) || ~ismatrix(s)

[Mathieu NOE]

can you share th txt file that generates this error ?

can you copy the output of whos from your workspace ? I'm interested to see what is in vraibales str and tmp ...

tx

[fadzhi]

i have attached the files and whos

Name Size Bytes Class Attributes

A 9x1 970344 cell

D 1x25 50 char

M 6732x18 969408 double

N 1x1 8 double

S 9x1 8061 struct

data 4386x2 70176 double

fid 1x1 8 double

fmt 1x36 72 char

k 1x1 8 double

n 1x1 8 double

n_lines 1x2 16 double

out 6732x2 107712 double

result 9x2 144 double

str 1x1 258 cell

tmp 0x0 0 cell

Answer 2

[fadzhi]

I found out that the units are problematic....I want to extract Dehnrate which also has a unit 1/s, 'Dehnrate: 10.0 [1/s] ', so i think somehow this 1 is problematic because it works for other quantities

[Mathieu NOE]

ok , so Ifixed the problem by selecting only the first numerical field

tested for lines 6 to 11 all together - so far so good :

n_lines = (6:11); % define lines to read
result = zeros(N,numel(n_lines));

for k = 1:N
    fid = fopen(fullfile(D,S(k).name), 'r'); % open file
    for n = 1:numel(n_lines)
        str = textscan(fid, '%s', 1, 'Headerlines', n_lines(n)-1, 'Delimiter' ,'\n'); % change %s (string) to %f to get first numerical value (does not work ??)
        tmp = regexp(char(str{1}),'-?\d+\.?\d*|-?\d*\.?\d+','match'); % extract numerical content of string
        tmp2 = tmp(1);
        result(k,n) = str2num(tmp2{:});
        frewind(fid) % set file position back to the start
    end
    fclose(fid); % close file
end

[Mathieu NOE]

this is another alternative using extractBetween , if you have release above R2017a

n_lines = (6:11); % define lines to read
result = zeros(N,numel(n_lines));

for k = 1:N
    fid = fopen(fullfile(D,S(k).name), 'r'); % open file
    for n = 1:numel(n_lines)
        str = textscan(fid, '%s', 1, 'Headerlines', n_lines(n)-1, 'Delimiter' ,'\n'); % change %s (string) to %f to get first numerical value (does not work ??)
        tmp2 = extractBetween(char(str{1}),':','[');
        result(k,n) = str2num(tmp2{:});
        frewind(fid) % set file position back to the start
    end
    fclose(fid); % close file
end

[fadzhi]

Many thanks...working fine

[Mathieu NOE]

Glad it helped !