Matlab reads file with different order

Hello ,

Can anyone help me as i put into matlab this txt file and it read it like that :

 0.9011 0.5400
 0.8480 1.4457
 0.6744 1.180

thanks in advance

[per isakson]

How exactly did you read the txt-file?

[chntua chntua]

i use fopen to open the txt file and fscanf to print the matrix

Answer 1

[per isakson]

>> fid = fopen('RQ_par.txt');
>> fs = fscanf( fid, '%f' )
fs =
       0.9011
        0.848
       0.6744
         0.54
       1.4457
         1.18
>> fclose(fid);

This shows how the numbers are stored in a sequence in the file on the disk. Then the reading function "decides" what are rows and what are columns. Matlab is "column major". C is row major.

Two better alternatives to read your file with R2018b are

>> dlmread('RQ_par.txt') 
ans =
       0.9011        0.848
       0.6744         0.54
       1.4457         1.18
>> rq = load('RQ_par.txt')
rq =
       0.9011        0.848
       0.6744         0.54
       1.4457         1.18
>> 

[chntua chntua]

if you please check my code if you can explain to me why it does not read it with the same order as in txt file

[per isakson]

"check my code" where do I find your code?

[chntua chntua]

here

[per isakson]

I try to say that "the same order as in txt file" is exactly what fscanf does. (You have to read the documentation carefully.) The statement

RQ = fscanf(combpar_1,'%f',[k,2]);

reads the data of the file to a vector and then reshapes that vector accourding to [k,2], i.e. puts the first three values in the first column (column major) and the following three values in the second column.

[chntua chntua]

yes but the order says A = fscanf(fileid,format spec , sizeA) . i want the size to be k lines which is 3 and 2 columns. how can i do that ?

[per isakson]

"want the size to be k lines which is 3 and 2 columns" Isn't that exactly what you get?

[chntua chntua]

yes but without changing position of elements. i want the elements of the matrix to be in the same position as in the txt file. how can i get that ?

[per isakson]

Read my answer and my comments once more. I cannot explain better.

[chntua chntua]

okay thanks a lot for your time !

Answer 2

[John D'Errico]

Must I point out the data in that file are arranged as:

data = textread('RQ_par.txt')
data =
                    0.9011                     0.848
                    0.6744                      0.54
                    1.4457                      1.18

MATLAB will read in each line, one at a time. That is how the file is set up.

If you want to change the order to a different order, it is not how you read the file in, but how you perform the re-arrangment.

data = reshape(data',3,2)
data =
                    0.9011                      0.54
                     0.848                    1.4457
                    0.6744                      1.18

[chntua chntua]

yes but the problem is that matlab does not read it as in text file. can you please check my code ? it is just 4 lines.