Combine two data frames to put identical rows adjacent
<p>I have to matrices (or data frames) that contain the same column and rownames. 
The rownames of matrix 1 has an ID called <code>dataTissue</code>, the rownames of matrix 2 has the ID <code>dataSerum</code>. I would like to combine the two matrices where identical rows are placed adjacent (on top of each other). Please see my desired output. 
I was thinking of using <code>rbind</code>, but I am not sure how to get this structure. </p>

<p>matrix 1:</p>

<pre><code>&gt; head(TumorTissue3)
                            020 045 080  082  084  086  088  090  091  092  094  096 1018   102 1065
dataTissue.hsa-let-7a-2-3p    1   0   1    0    0    0    1    1    0    2    0    0    0     5    0
dataTissue.hsa-let-7a-3p      2   0   0    0    1    0    1    1    0    2    1    1    1     1    0
dataTissue.hsa-let-7a-5p     67  12  25   34   40  115   42   33   26   58   22  149   64   178   52
dataTissue.hsa-let-7b-3p     11   5  10   15    1   34   29   59   16   30   11   44   11    65    3
dataTissue.hsa-let-7b-5p   4289 689 902 3340 3947 7326 3146 6249 2032 5664 1657 6619 1577 21132  720
dataTissue.hsa-let-7c-3p      1   0   0    2    0    9    2   13    2   10    2   13    5     9    0
                           1068 1104  112  113 1167 1196   120  121 1222 1237 1241 1302 1304  1322  134
dataTissue.hsa-let-7a-2-3p    2   11    0    0    0    0     3    0    2    1    0    0    3     5    1
dataTissue.hsa-let-7a-3p      0    0    1    0    0    1     0    0    1    4    1    0    2     3    0
dataTissue.hsa-let-7a-5p     70  266   60    8   29   99    90   37  102   93   28   22  156   214  176
dataTissue.hsa-let-7b-3p     14   15   24   12    8    8    43   25   14   33    9   12   16    38   11
dataTissue.hsa-let-7b-5p   1780 4185 5797 1168 1039 1006 10818 3269 2893 8847 3136 4990 1798 10142 3248
dataTissue.hsa-let-7c-3p      5    7    5    2    1    3     3    3    1   10   27    1   17    11    3
                           1372 140  145  146  1474 1532  1540 157   158 1588 1604   161 1743   176
dataTissue.hsa-let-7a-2-3p    0   0    0    0     6    1    10   0     6    1    0     1    0     2
dataTissue.hsa-let-7a-3p      1   0    1    0     0    1     0   0     3    0    0     2    0     1
dataTissue.hsa-let-7a-5p     18   1   53   17   129   54   110   2   165   70   51   165   81    77
dataTissue.hsa-let-7b-3p      3   0   22   12    46    3    60   0    79    9   15    40    3    50
dataTissue.hsa-let-7b-5p    931 245 3707 3632 16730 2653 13619  93 27568 3485 6202 18206 3094 11185
dataTissue.hsa-let-7c-3p      1   0   12    0    10    0     5   0    20   10    8     7    2     9
                           1808 1809  185 1859  186 1894  192 201  204   21   215  2218  236    27   32
dataTissue.hsa-let-7a-2-3p    2    1    1    0    1    0    0   0    3    0     2     6    0     3    5
dataTissue.hsa-let-7a-3p      0    0    0    0    1    0    0   0    1    0     3     3    0     1    0
dataTissue.hsa-let-7a-5p     33  160   56   16   92   63   90   3  119   58   116    46   37   137   40
dataTissue.hsa-let-7b-3p     11    1   23   10   18    3   48  14   34   16    54    23   12    96   33
dataTissue.hsa-let-7b-5p   3497  548 5575 2886 6664 1030 5895 604 8151 4076 14150 11132 2154 24793 5654
dataTissue.hsa-let-7c-3p      3    3    5    6    6    2    4   2    6    9    20     6    2    11    6
                             38   39    45   46 bf33  d10 HEP014 HEP015  mm7  s26 TxHEP-014 TxHEP-015
dataTissue.hsa-let-7a-2-3p    0    0     6    0    0    0      1      2    2    4         0         1
dataTissue.hsa-let-7a-3p      0    0     0    2    0    2      2      0    1    2         0         1
dataTissue.hsa-let-7a-5p     18   75   192   41   41   88     55    119   24  112       223        25
dataTissue.hsa-let-7b-3p      6   16    56   11   17   24      8     29   12   29         7        18
dataTissue.hsa-let-7b-5p   1648 2805 19275 1769 4554 5316   1552   7605 2369 7495     33820      2144
dataTissue.hsa-let-7c-3p      3    1    14    2    2    3      6     18    1   23         3         2
                           TxHEP-018 vs29
dataTissue.hsa-let-7a-2-3p         1    1
dataTissue.hsa-let-7a-3p           0    0
dataTissue.hsa-let-7a-5p          13   50
dataTissue.hsa-let-7b-3p          23   47
dataTissue.hsa-let-7b-5p        1631 4990
dataTissue.hsa-let-7c-3p           1   11
</code></pre>

<p>matrix 2:     </p>

<pre><code>&gt; head(Serum3)
                           020  045 080  082  084  086  088 090 091  092  094  096  1018  102 1065 1068
dataSerum.hsa-let-7a-2-3p    0    0   0    0    0    0    0   0   0    0    0    0     0    0    0    0
dataSerum.hsa-let-7a-3p      4    2   0    2  329    1  186   0   2    4    1    6    13    7   15    3
dataSerum.hsa-let-7a-5p    988 2033 587 1480 4035 1167 4641 761 668 4118 6040 2660 10368 5802 5668 2709
dataSerum.hsa-let-7b-3p      9    8   4   18   76    3   62   1   5   24    9    9    41   10   30    6
dataSerum.hsa-let-7b-5p   1499  849 108  868 3197  202 2411 273 224 1309  943  822  5819 1594 3335 1164
dataSerum.hsa-let-7c-3p      0    0   0    0   29    0   11   0   0    0    5    0     2    0    0    1
                           1104  112  113 1167 1196  120 121 1222 1237 1241 1302 1304 1322  134 1372
dataSerum.hsa-let-7a-2-3p     0    0    0    0    1    0   0    0    0    0    0    0    0    0    0
dataSerum.hsa-let-7a-3p      15    2    0    8    5    2   0   11   13   51    4    0    1    7    0
dataSerum.hsa-let-7a-5p   30222 1836 1518 3902 5122 4597 983 3809 6310 3165 4023  434 2489 1496  600
dataSerum.hsa-let-7b-3p      57    2    1   14   19   14   2   14   35  162   10    0   10   11    6
dataSerum.hsa-let-7b-5p   11314  329  354 2169 2277  747 256 1157 3328 3662 1057  274 1267  991  305
dataSerum.hsa-let-7c-3p       0    0    0    0    0    0   0    0    0   10    0    0    0    0    0
                           140   145 146 1474 1532 1540 157   158 1588 1604   161 1743  176 1808 1809
dataSerum.hsa-let-7a-2-3p    0     0   0    0    0    0   0     0    0    0     0    0    0    0    0
dataSerum.hsa-let-7a-3p     27    10   0    2    2    5   0    40    0    0    19    0    1    4    4
dataSerum.hsa-let-7a-5p   5364 12731 670  473 1045  767 927 49689  535    8 78671  757 1502 1146  539
dataSerum.hsa-let-7b-3p     63    37   1    3   14    5  10    59    1    0    56    6    3   12    6
dataSerum.hsa-let-7b-5p   2262  3209  88  363  759  459 309 13482  234    3 15113 1064  545  587  569
dataSerum.hsa-let-7c-3p      6     0   0    0    0    0   1     0    0    0     0    0    1    0    0
                            185 1859   186 1894  192   201   204   21    215 2218    236    27   32
dataSerum.hsa-let-7a-2-3p     0    0     0    0    0     3     0    0      0    0      0     0    0
dataSerum.hsa-let-7a-3p      16    0   101    3    7   346    10    1     93    0    305     6   12
dataSerum.hsa-let-7a-5p   42694  528 18730  498 3410 20484 11907 1031 474051 2185 299085 14576 9218
dataSerum.hsa-let-7b-3p      24    7   164   14   16    85    29   12    111    9    145    32   12
dataSerum.hsa-let-7b-5p    5454  216  4647  182 1149  8973  2645  147  72681  807  46354  4672 2375
dataSerum.hsa-let-7c-3p       0    0     9    0    0    32     0    0      0    0      3     1    0
                            38   39   45   46 bf33 d10 HEP014 HEP015 mm7  s26 TxHEP-014 TxHEP-015
dataSerum.hsa-let-7a-2-3p    0    0    0    1    0   0      0      0   0    0         0         0
dataSerum.hsa-let-7a-3p      9   17    6  119   27   0      1      5   0   10         7         1
dataSerum.hsa-let-7a-5p   2395 4382 8361 9747 6440 616   2981   5851 291 1386      3709      2494
dataSerum.hsa-let-7b-3p     18   28   24  104   33   6     12     24   5   36         2        11
dataSerum.hsa-let-7b-5p    690 1756 3425 3972 2330 136   1035   2152 235  638       555      1409
dataSerum.hsa-let-7c-3p      1    3    2   10    1   0      0      0   0    2         0         0
                          TxHEP-018 vs29
dataSerum.hsa-let-7a-2-3p         0    0
dataSerum.hsa-let-7a-3p           0    2
dataSerum.hsa-let-7a-5p         397  266
dataSerum.hsa-let-7b-3p           0    9
dataSerum.hsa-let-7b-5p          67  182
dataSerum.hsa-let-7c-3p           0    0
</code></pre>

<p>Output:</p>

<pre><code>dataTissue.hsa-let-7a-2-3p 23  24  35 ....
dataSerum.hsa-let-7a-2-3p 42 535  54 ....
dataTissue.hsa-let-7a-3p 234  224  35 ....
dataSerum.hsa-let-7a-3p 2 33  54 ....
</code></pre>