How can i delete rows with zeros from a matrix and rebuild the matrix?

I have this matrix, as an example, because the problem is a nxm one with a more complex program, so i hope this may help.

>> A=rand(9,3)
A =
         0.575208595078466          0.73172238565867         0.368484596490336
        0.0597795429471558         0.647745963136307          0.62561856072969
         0.234779913372406         0.450923706430945         0.780227435151377
         0.353158571222071         0.547008892286345        0.0811257688657853
         0.821194040197959         0.296320805607773          0.92938597096873
        0.0154034376515551         0.744692807074156         0.775712678608402
        0.0430238016578078         0.188955015032545         0.486791632403172
         0.168990029462704         0.686775433365315         0.435858588580919
         0.649115474956452          0.18351115573727         0.446783749429806
>> B=[A;zeros(1,3)]
B =
         0.575208595078466          0.73172238565867         0.368484596490336
        0.0597795429471558         0.647745963136307          0.62561856072969
         0.234779913372406         0.450923706430945         0.780227435151377
         0.353158571222071         0.547008892286345        0.0811257688657853
         0.821194040197959         0.296320805607773          0.92938597096873
        0.0154034376515551         0.744692807074156         0.775712678608402
        0.0430238016578078         0.188955015032545         0.486791632403172
         0.168990029462704         0.686775433365315         0.435858588580919
         0.649115474956452          0.18351115573727         0.446783749429806
                         0                         0                         0
>> C=[0:9]
C =
     0     1     2     3     4     5     6     7     8     9
>> D=C'
D =
     0
     1
     2
     3
     4
     5
     6
     7
     8
     9
>> E=[D,B]
E =
                         0         0.575208595078466          0.73172238565867         0.368484596490336
                         1        0.0597795429471558         0.647745963136307          0.62561856072969
                         2         0.234779913372406         0.450923706430945         0.780227435151377
                         3         0.353158571222071         0.547008892286345        0.0811257688657853
                         4         0.821194040197959         0.296320805607773          0.92938597096873
                         5        0.0154034376515551         0.744692807074156         0.775712678608402
                         6        0.0430238016578078         0.188955015032545         0.486791632403172
                         7         0.168990029462704         0.686775433365315         0.435858588580919
                         8         0.649115474956452          0.18351115573727         0.446783749429806
                         9                         0                         0                         0
>>

My question is how can transform matrix E into

    E =
                             0         0.575208595078466          0.73172238565867         0.368484596490336
                             1        0.0597795429471558         0.647745963136307          0.62561856072969
                             2         0.234779913372406         0.450923706430945         0.780227435151377
                             3         0.353158571222071         0.547008892286345        0.0811257688657853
                             4         0.821194040197959         0.296320805607773          0.92938597096873
                             5        0.0154034376515551         0.744692807074156         0.775712678608402
                             6        0.0430238016578078         0.188955015032545         0.486791632403172
                             7         0.168990029462704         0.686775433365315         0.435858588580919
                             8         0.649115474956452          0.18351115573727         0.446783749429806

in order to print it and to write it in a txt file easily without the zeros. And remember, as this is an nxm matrix it can be also...

E =
                         0         0.575208595078466          0.73172238565867         0.368484596490336
                         1        0.0597795429471558         0.647745963136307          0.62561856072969
                         2         0.234779913372406         0.450923706430945         0.780227435151377
                         3         0.353158571222071         0.547008892286345        0.0811257688657853
                         4         0.821194040197959         0.296320805607773          0.92938597096873
                         5        0.0154034376515551         0.744692807074156         0.775712678608402
                         6        0.0430238016578078         0.188955015032545         0.486791632403172
                         7         0.168990029462704         0.686775433365315         0.435858588580919
                         8         0.649115474956452          0.18351115573727         0.446783749429806
                         9                         0                         0                         0
                        10                         0                         0                         0

Also, i would like to transform a matrix like

E =
                         0         0.575208595078466          0.73172238565867         0.368484596490336
                         1        0.0597795429471558         0.647745963136307          0.62561856072969
                         2         0.234779913372406         0.450923706430945         0.780227435151377
                         3         0.353158571222071         0.547008892286345        0.0811257688657853
                         4         0.821194040197959         0.296320805607773          0.92938597096873
                         5        0.0154034376515551         0.744692807074156         0.775712678608402
                         6        0.0430238016578078         0.188955015032545         0.486791632403172
                         7         0.168990029462704         0.686775433365315         0.435858588580919
                         8         0.649115474956452          0.18351115573727         0.446783749429806
                         0                         0                         0                         0
                         0                         0                         0                         0

in the same as before.

E =
                         0         0.575208595078466          0.73172238565867         0.368484596490336
                         1        0.0597795429471558         0.647745963136307          0.62561856072969
                         2         0.234779913372406         0.450923706430945         0.780227435151377
                         3         0.353158571222071         0.547008892286345        0.0811257688657853
                         4         0.821194040197959         0.296320805607773          0.92938597096873
                         5        0.0154034376515551         0.744692807074156         0.775712678608402
                         6        0.0430238016578078         0.188955015032545         0.486791632403172
                         7         0.168990029462704         0.686775433365315         0.435858588580919
                         8         0.649115474956452          0.18351115573727         0.446783749429806

Thank you very much.

Answer 1

[dbmn]

A not so easily readable solution would be the following

% Create a zero vector to compare to 
  a=zeros(1,size(E,2)-1);
% Compare to that vector and check if each element is the same
  index = [sum([E(:,2:end)==a]')==(size(E,2)-1)]';
% delete all the rows that are the same
  E(index, :)=[];

[Pablo Álvarez Rodríguez]

I will have to try this one for the zero cases, thanks... bit i think it won't help the numbered one

[dbmn]

With the numbered one it should work as well, because the first row is not taken into consideration at all with E(:, 2:end). Hence it does not matter what is written in the first column.

Geoff`s solution is more beautiful than mine - so you might want to combine the two

Answer 2

[Geoff Hayes]

Pablo - you could try the following but it assumes that equality with zero will always return true (which isn't necessarily the case unless you are using integers)

 A = rand(9,3);
 A = [A ; zeros(1,3)];
 A(all(A==0,2),:) = [];

In the above, we use all to find all rows of A that have all zeros. all(A==0,2) will return a column array of zeros and ones where a one indicates all zeros in that row. We then use that column array to set all zero rows to the empty array which will remove the row from A.

[Pablo Álvarez Rodríguez]

I am using integers for indexing the rows (first column)

It may help in the case of all rows as zero.