how to get some values from many text files and put them into the calculation ( please help)

hello,

I have some text files have same content such as the text i shared below. and i need value of i need the value of Area, xbar,ybar,IXXw and IYYw. how can i get them from,for example,5 text file which have name data1, data2, data3, data4, data5 and for example i want to calculate the mean value of areas?

============================================================
Information listing created by :  T40118
Date                           :  29.08.2013 11:07:12
Current work part              :  FA00AAC41319/002
Node name                      :  tofdsk03221
============================================================
Work Part            FA00AAC41319/002 : 08/29/13 11:07 
Information Units    kg - mm

Perimeter            =     765.13878188660
Area                 =   11875.0

First Moments
MY                   =  -109375.0
MX                   =  -1062500.0

Center of Mass
Xbar                 =      -9.21052631578950
Ybar                 =     -89.4736842105260

Moments of Inertia (Work)
Ixxw                 =  110677083.333330
Iyyw                 =  25716145.8333330

Moments of Inertia (Centroidal)
Ixx                  =  15611293.8596490
Iyy                  =  24708744.5175440

Moment of Inertia (Polar)
                     =  40320038.3771930

Product of Inertia (Work)
Pxyw                 =  20507812.50

Product of Inertia (Centroidal)
Pxy                  =  10721628.2894740

Radii of Gyration (Work)
Rgxw                 =      96.5410557151540
Rgyw                 =      46.5356871168630

Radii of Gyration (Centroidal)
Rgx                  =      36.2578994481410
Rgy                  =      45.6150893940230

Radii of Gyration (Polar)
                     =      58.2698176830530

Principal Axes

Answer 1

[Matt Kindig]

One approach using regular expressions:

%variables to average over
AveVariables = {'Area', 'xbar', 'ybar', 'IXXw', 'IYYw'};  
AveVariables = lower(AveVariables);  %remove case

Files = dir('data*.txt');  %get all dataXX files
nFiles = length(Files);
AllData = NaN( nFiles, length(AveVariables));  %variables for each file

for k = 1:nFiles;
  File = Files(k).name;
  str = fileread(File);  %read file into string
  pat = '\(*(?<var>[A-Z]+)\)*\s+\=\s+(?<val>[0-9\.\-]+)';  %define pattern
  %search pattern is:
  %[series of letters, possibly surrounded by parens] = [signed decimal number]
  variables = regexpi(str, pat, 'names');    %match pattern
  values = {variables.val};
  vars = lower({variables.var});
  [tf,loc]=ismember( AveVariables, vars);  %compare to target variables
  values = str2double(values(loc(tf)));  %convert to numeric
  AllData(k,tf)=values;   %add to AllData matrix
end

AveData=nanmean(AllData,1);  %average over files

[Yusuf]

thank you for your answer, it works well but just one more question which is that how i can use those values, for example, i want to define n : Xbar(average)/2 , when i try to do this,n = 'xbar'/2, i got matrix like this

   60.0000   49.0000   48.5000   57.0000
but i just want to use avarage value of Xbar and divide it by two, how i can do this ?

Answer 2

[Walter Roberson]

AveVariables = {'Area', 'xbar', 'ybar', 'IXXw', 'IYYw'};  %variables to average over
matchpats = cellfun( @(P) ['^' P '\s*=\s*(?<' P '>\S+)\s*$' ], AveVariables, 'Uniform', 0);

allvals = cell2struct( cell(length(AveVariables,1), AveVariables);

Files = dir('data*.txt');  %get files
for K = 1 : length(files)
   thistext = fileread( files(K).name );
   matchtokens = regexp( thistext, matchpats, 'tokens', 'lineanchors' );
   allvals(K) = matchtokens;
end

Now allvals will be a struct array with the K'th element being a struct whose fields are named according to the variable names. With this version of the code, each field will contain a string. If all of the variable are numeric and you want them converted, you could use

allvals(K) = structfun( @str2double, matchtokens, 'Uniform', 0 );