Getting "Subscripted assignment dimension mismatch" error message

I made a function that extracts from a text file some numeric data. I want my function to return my data in a matrix with 36 rows and N columns but for some reason, when i run my function it stops the reading on 6th row and gives me this error ''Subscripted assignment dimension mismatch". To arrange my data in the final matrix after reading the lines from the text file and converting them to numeric I wrote:

j=1;
while ~feof(fid)
 line1 = fgets(fid);
 data1 = str2num(line1(1:2));
 data2= str2num(line1(4:5));
 etc.
 matrix(1,j)=data1; 
 matrix(2,j)=data2
 .
 matrix(36,j)=data36..
 j=j+1
end

But as I said when I run the function it stops on 6th row..But if I delete from my code until matrix(5,j)=data5 it works just fine.

[lvn]

It would help if you post/attach your input file and complete code.

The code fragment you posted also seems to be a bit redundant, eg.

   data1 = str2num(line1(1:2));
   ...
   matrix(1,j)=data1;

can be written as

matrix(1,j)=str2num(line1(1:2));

[Sebastian Ciuban]

Here it is. Thank you very much for your assistance. The input file is baia.13n

Answer 1

[per isakson]

Your way of parsing the text file is laborious and error prone.

    K>> Min = str2num(line1(17:19));
    K>> Min
    Min =
         9     4

The value of Min is .<1x2 double>, which causes the error

    K>> eph(6,j)=Min;
    Subscripted assignment dimension mismatch.

where line1 is

    8 13 03 11 17 59 44.0 5.066394805908D-06 2.273736754432D-13 .....

Replace

    str2num(line1(17:19))

by

    str2num(line1(16:18))

But the following line of code is also in error.

[Sebastian Ciuban]

Thank you!

[Sebastian Ciuban]

Can I ask you 1 more thing, how I can simplify my code?..As you said, it is error prone.

Answer 2

[per isakson]

Your file is not easy to read and parse with Matlab

• The file is fixed width formatted. There are no delimiter between the values - one must rely on the positions.
• fscanf doesn't parse "D+01". However, textscan does(?).
• The file contains one header and many blocks of data. All the data blocks have the same format. The data "values" are 19 characters wide.
• Each block contains a number, datetime and 29 different values
• I trust that the format will not change. A description of the format used to write the file would have helped.

This is the beginning of the file. I've truncated the rows to avoid wrapping.

         2.10           NAVIGATION DATA                         RINEX V
    SPIDER V4,3,0,4633  NACLR               2013 03 13 00:04    PGM / R
       2.1420D-08  7.4506D-09 -1.1921D-07  0.0000D+00           ION ALP
       1.2288D+05  0.0000D+00 -2.6214D+05  1.9661D+05           ION BET
        4.656612873077D-09 1.687538997430D-14   503808     1731 DELTA-U
        16                                                      LEAP SE
                                                                END OF 
     1 13 03 11 20 00  0.0 6.680842489004D-06 2.955857780762D-12 0.0000
        8.700000000000D+01-3.934375000000D+01 4.114457219373D-09 2.0198
       -1.996755599976D-06 1.641191076487D-03 1.329556107521D-05 5.1537
        1.584000000000D+05-2.421438694000D-08-8.571340308443D-02-2.4214
        9.607402942553D-01 1.195625000000D+02 3.658472115763D-01-7.8521
       -8.357491088073D-11 1.000000000000D+00 1.731000000000D+03 0.0000
        2.000000000000D+00 0.000000000000D+00 8.381903171539D-09 8.7000
        1.511400000000D+05 0.000000000000D+00
     2 13 03 12 00 00  0.0 4.219263792038D-04 1.477928890381D-12 0.0000
        5.900000000000D+01-4.168750000000D+01 4.622692451051D-09-1.3010
       -2.242624759674D-06 1.214739750139D-02 1.278705894947D-05 5.1536
        1.728000000000D+05 2.700835466385D-07-1.057868232687D-01-2.5331
        9.392481697649D-01 1.218125000000D+02-2.648953410445D+00-7.9846
       -1.810789712620D-10 1.000000000000D+00 1.731000000000D+03 0.0000
        2.000000000000D+00 0.000000000000D+00-1.769512891769D-08 5.9000
        1.655400000000D+05 0.000000000000D+00

I've written a function, baia_read, which reads the file. It returns a structure and the data seems to have ended up in the correct place ( needs to be checked ).

    >> baia = read_baia();
    >> baia
    baia = 
                   PNR: [212x1 double]
               datevec: [212x6 double]
              SVclbias: [212x1 double]
             SVcldrift: [212x1 double]
        SVcldrift_rate: [212x1 double]
                  IODE: [212x1 double]
                   Crs: [212x1 double]
                    Dn: [212x1 double]
                    M0: [212x1 double]
                   Cuc: [212x1 double]
                     e: [212x1 double]
                   Cus: [212x1 double]
                sqrt_a: [212x1 double]
                   toe: [212x1 double]
                   Cic: [212x1 double]
                 OMEGA: [212x1 double]
                   Cis: [212x1 double]
                    I0: [212x1 double]
                   Crc: [212x1 double]
                 Omega: [212x1 double]
              Omegadot: [212x1 double]
                  Idot: [212x1 double]
               L2codes: [212x1 double]
               Gpsweek: [212x1 double]
               L2Pflag: [212x1 double]
           SV_accuracy: [212x1 double]
             SV_health: [212x1 double]
                   tgd: [212x1 double]
                  iodc: [212x1 double]
                    tt: [212x1 double]
                    fi: [212x1 double]
    >>

where

    function    baia = read_baia( filespec )

        if nargin == 0
            filespec = 'baia.13n';
        end

    %   read the text file to a string vector    
        buffer   = fileread( filespec );

    %   Strip off the header    
        buffer = regexp( buffer, '(?<=END OF HEADER\s+?\r\n).+$' ...
                                , 'match', 'once'                );

        buffer = strrep( buffer, 'D', 'e' );

    %   Regular expressions, which match the PNR-date-time strings. 
    %   It could be made more specific. This matches a row of 22 spaces. 
        xpr_PRN = '([ 0-9]{2})';
        xpr_dt  ...  
        = '([ 0-9]{3}[ 0-9]{3}[ 0-9]{3}[ 0-9]{3}[ 0-9]{3}[ 0-9\.]{5})'; 

    %   Determine the beginning and end of the blocks of data      
        block_start = regexp( buffer, [xpr_PRN,xpr_dt] );
        block_end   = [ block_start(2:end)-1, length( buffer ) ];
        nBlocks     = length( block_start );

    %   Format of the PNR-date-time fields and the data. The code here 
    %   is formatted to look similar to the chunk of data in the file.
        frm_ndt = '%2f%3f%3f%3f%3f%3f%5f';
        frm_val = cat( 2,   '%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f%19f%19f\r\n'  ...
                    ,   '%22f%19f\r\n'          );

    %   The names of the variables in the order they appear in the block 
    %   of data.            
        line1   = {'SVclbias','SVcldrift','SVcldrift_rate'};
        line2   = {'IODE','Crs','Dn','M0'};
        line3   = {'Cuc','e','Cus','sqrt_a'};
        line4   = {'toe','Cic','OMEGA','Cis'};
        line5   = {'I0','Crc','Omega','Omegadot'};
        line6   = {'Idot','L2codes','Gpsweek','L2Pflag'};
        line7   = {'SV_accuracy','SV_health','tgd','iodc'};
        line8   = {'tt','fi'};

        variable_names = ['PNR','datevec'                       ...
            ,   line1,line2,line3,line4,line5,line6,line7,line8 ];

    %   Allocate memory for the result.    
        baia = cell2struct( repmat( {nan(nBlocks,1)}     ...     
                        ,   [1,length(variable_names)] ) ...
                        ,   variable_names, 2            );

        baia.datevec = nan(nBlocks,6);

        for ii =  1 : length( block_start )     % loop over all blocks

            num = sscanf                                                ...
                ( buffer(block_start(ii):block_start(ii)+21 ), frm_ndt  ); 

            baia.PNR(ii)        = num(1);
            baia.datevec(ii,:)  = num(2:end);

            num = sscanf                                            ...
                ( buffer(block_start(ii)+22:block_end(ii)), frm_val ); 

            for jj = 3 : length( variable_names )   % loop over all variables
                baia.(variable_names{jj})(ii) = num(jj-2);  
            end
        end
    end

[Sebastian Ciuban]

The description for this type of file http://gage14.upc.es/gLAB/HTML/GPS_Navigation_Rinex_v2.11.html

Those data blocks have broadcast parameters at a certain time, that I need for computing a certain satellite orbit

[per isakson]

• Are you aware of TIMESPLITRINEX, by Ian Howat?
• I checked TABLE A16 of RINEX: The Receiver Independent Exchange Format Version 2.11 describes the format. Good old FORTRAN format specifiers.I think I got it right.

[Sebastian Ciuban]

You are very helpful. Thank you very much

[per isakson]

@Timothy, did you fail to read OP's file, 'baia.13n', with the function, read_baia?

[Timothy]

No. I read the file and the script written. I edited the script and have updated my post. http://www.mathworks.com/matlabcentral/newsreader/view_thread/336569

[per isakson]

Please, post the files as attachments here. / per

[Image Analyst]

You mean in the Answers forum rather than the newsgroup. Not as a comment anywhere in this (Ciuban's) post, but as a brand new post/question in the forum.

[Timothy]

I got it figured out thanks for the help.

Answer 3

[Walter Roberson]

feof issue. See http://www.mathworks.co.uk/matlabcentral/answers/21210-arrarys

[Sebastian Ciuban]

Well I do get this error ,,Subscripted assignment dimension mismatch.

Error in readRINEXnav (line 76) matrix(6,j)=Minute; "

It seems I have a problem in preallocating memory to build my matrix with the elements extracted and converted to numbers from my file.

[Walter Roberson]

That line of code does not exist in the readRINEXnav.m source you put into the .zip file.

[Sebastian Ciuban]

matrix(6,j)=Minute its the same with eph(6,j)=Min. Sorry for the mistake

[Walter Roberson]

Did you fix your use of feof as indicated needs to be done in the item I linked to?

[Sebastian Ciuban]

I mean ,,matrix" is the same with ,,eph"..I wrote ,,matrix" in my question to be more explicit

[Sebastian Ciuban]

No, I don't know how.Because I am new to Matlab and lately I am ,,bombed" with new information about this software and my brain won't process so much at the same time :))..I'm doing my best but it seems is not enough