re arrange/shape matrix according to the position of a index value in array.

Dear friends, many thanks for helping me, it was succesfull.

I would like to help me in this task, having the next file as example, I will try to explain with only a reduced number of values of the file.

https://www.dropbox.com/s/y3ehqalm3cxmzuj/x.txt

Below is what I have to start, I would need something what is able to do what is shown in "desired output"

 imput: 
      306,000  305,952  304,683  302,265  300,219
      306,000  306,008  304,977  302,450  299,846
      306,000  305,962  304,840  302,413  299,812
      306,000  306,051  305,051  302,396  299,877
      306,000  306,003  304,891  302,163  300,017
      306,000  306,004  305,002  301,997  300,186
      406,000  406,016  404,943  402,467  400,224
      406,000  406,009  404,961  402,483  400,361
      406,000  406,014  404,852  402,547  400,287
      406,000  406,043  404,990  402,520  400,372
      406,000  406,048  405,105  402,425  400,817
      406,000  406,034  404,928  402,425  400,623
      506,000  506,038  505,182  502,518  500,878
      506,000  506,003  505,208  502,728  500,684
      506,000  505,971  505,110  502,841  501,118
      506,000  505,979  505,083  502,644  500,922
      506,000  505,985  505,065  502,942  500,955
      506,000  506,062  505,067  502,818  501,280

    desired output:

       (first 3 rows of all groups of same index)
      306,000  305,952  304,683  302,265  300,219 
      406,000  406,016  404,943  402,467  400,224
      506,000  506,003  505,208  502,728  500,684

      (second 3 rows of all groups of same index)

      306,000  306,008  304,977  302,450  299,846 
      406,000  406,009  404,961  402,483  400,361
      506,000  506,003  505,208  502,728  500,684 

      (third 3 rows of all groups of same index

      306,000  305,962  304,840  302,413  299,812 
      406,000  406,014  404,852  402,547  400,287
      506,000  505,971  505,110  502,841  501,118

      fourth 3 rows of all groups of same index 

      306,000  306,051  305,051  302,396  299,877  
      406,000  406,043  404,990  402,520  400,372
      506,000  505,979  505,083  502,644  500,922

      fifth... 

      306,000  306,003  304,891  302,163  300,017  
      406,000  406,048  405,105  402,425  400,817
      506,000  505,985  505,065  502,942  500,955

      sitxh...

      306,000  306,004  305,002  301,997  300,186  
      406,000  406,034  404,928  402,425  400,623
      506,000  506,062  505,067  502,818  501,280

The desired output would be if, for instance, in the original file I have 234 indexed in groups of 6 rows, I would like to obtain at the end matrix of 39x5 , and the number of matrix is the length, or the amount of rows that I have per group.

I hope to have been clear. And, anyway, many thanks for your help. It was very useful for me, and I am doing little steps to learn how to program.

I know my question is tricky, but once I have the way, I will understand how it works.

Best Regards and heartfelt thanks

Miguel

[Andrei Bobrov]

repeated question

Answer 1

[Azzi Abdelmalek]

% If your_array is your cell array

[a,b]=unique(your_array(:,1),'stable');
n=size(your_array,1)/numel(a);
zz=reshape(your_array',size(your_array,2)*n,[])'
zz1=reshape(zz,size(zz,1),[],n);
out= cell2mat(arrayfun(@(x) zz1(:,:,x),(1:n)','un',0))

%or

[a,b]=unique(your_array(:,1),'stable');
n=size(your_array,1)/numel(a);
zz=reshape(your_array',size(your_array,2)*n,[])';
zz1=reshape(zz,size(zz,1),[],n);
q=permute(zz1,[2 1 3]);
out1=q(:,:)';

[Miguelcm90]

Dear Mr. Abdelmalek,

Many thanks for your reply,

I think it will work, If I need some extra help, I will let you know.

Best Regards,

Miguek

[Miguelcm90]

Dear Friend, your help works well,

Now, I would need to do the same as I asked in the question: "how to calculate differences inside an array , looping through a matrix and saving results" I do not want to repeat the question so as not to be repetitive.

I got this answer.

    [a,b]=unique(x(:,1),'stable');
    b=[b;size(x,1)];
    out=nan(size(x));
    for k=1:numel(b)-1
      i1=b(k)+1;
      i2=b(k+1)-1;
      out(i1:i2,:)=bsxfun(@minus,x(i1:i2,:),x(i1-1,:));
    end
    out(isnan(out(:,1)),:)=[];
    out=out(:,2:end)

Taking into account the results provided in this wire, below are shown only a sample of them see original file in:

https://www.dropbox.com/s/kpifg9z43x4me39/out.txt

     imput :

    306  305,952  304,683  302,265  300,219 (1)
    406  406,016  404,943  402,467  400,224 (2)
    506  506,038  505,182  502,518  500,878 (3)
    606  605,983  605,304  602,749  601,037 (4)
    706  705,992  705,459  703,378  701,678 (5)
    806  806,027  805,31  803,212  801,897 (6)
    906  906,015  905,542  903,513  902,139 (7)->jump
    306  306,008  304,977  302,45  299,846 (8)<-
    406  406,009  404,961  402,483  400,361 (9)
    506  506,003  505,208  502,728  500,684 (10)
    606  605,999  605,447  603,032  601,458 (11)
    706  706,012  705,41  703,335  702,125 (12)
    806  806,02  805,462  803,338  801,901 (13)
    906  906,014  905,25  903,571  901,725 (14)

desired output:
this should be the first group:

100  100,064  100,26  100,202  100,005 (row2-row1)
200     200,086  200,499  200,253  200,659 (row3-row1)
300     300,031  300,621  300,484  300,818 (row4-row1)
400     400,04  400,776  401,113  401,459 (row5-row1)
500     500,075  500,627  500,947  501,678 (row6-row1)
600     600,063  600,859  601,248  601,92  (row7-row1)->jump
100  100,001  99,984  100,033  100,515 (row9-row8)-<
200  199,995  200,231  200,278  200,838 (row10-row8)
300  299,991  300,47  300,582  301,612 (row11-row8)
400  400,004  400,433  400,885  402,279 (row12-row8)
500  500,012  500,485  500,888  502,055 (row13-row8)
600  600,006  600,273  601,121  601,879 (row14-row8)

the calculations, start substracting from the second row the first one. then, the from the third to the first one. as you can see in the output. It is like absolute references in Excel, but, changing this reference to the smallest value of the first columm. This first columnn is not used in the calculations but I think is useful to index the arrays. having the start in the smallest value, and ending the loop in the biggest value found in the columm/array.It would be good if it can be applied for more columms and more rows. I do not know if It is possible. Any help is welcome. I think the code to write , is quite similar as one is shown here.

Thank you very much for your help. and I hope your reply.

[Andrei Bobrov]

see ADD2 part in my answer

[Azzi Abdelmalek]

[a,b]=unique(your_array(:,1),'stable');
n=size(your_array,1)/numel(a);
zz=reshape(your_array',size(your_array,2)*n,[])';
zz1=reshape(zz,size(zz,1),[],n);
out=cell2mat(arrayfun(@(x) bsxfun(@minus,zz1(2:end,:,x),zz1(1,:,x)),(1:n)','un',0))

Answer 2

[Andrei Bobrov]

z=[306.000 305.952  304.683  302.265  300.219
306.000  306.008  304.977  302.450  299.846
306.000  305.962  304.840  302.413  299.812
306.000  306.051  305.051  302.396  299.877
306.000  306.003  304.891  302.163  300.017
306.000  306.004  305.002  301.997  300.186
406.000  406.016  404.943  402.467  400.224
406.000  406.009  404.961  402.483  400.361
406.000  406.014  404.852  402.547  400.287
406.000  406.043  404.990  402.520  400.372
406.000  406.048  405.105  402.425  400.817
406.000  406.034  404.928  402.425  400.623
506.000  506.038  505.182  502.518  500.878
506.000  506.003  505.208  502.728  500.684
506.000  505.971  505.110  502.841  501.118
506.000  505.979  505.083  502.644  500.922
506.000  505.985  505.065  502.942  500.955
506.000  506.062  505.067  502.818  501.280];

out = permute(reshape(z,[],3,size(z,2)),[2 3 1]);

ADD

s = size(z);
n = s(1)/numel(unique(z(:,1)));
out = reshape(permute(reshape(z,n,[],s(2)),[2 1 3]),s);

ADD 2

m = dlmread('path_your_out.txt');
t=[true;diff(m(:,1)) < 0];
out = m-n(cumsum(t),:);
out = out(any(out,2),:);