Help needed in R

Dear ALL:

I have two quick questions about how to perform some steps in R. 
Could you please see the attached MS file if the data not clean 
enough in this email.

Thank you so much for all your helps.


Abou



Here it is:
=========================

Consider the following matrix:

data<-matrix(c(2,2,12,2,1,10,10,4,10,1,1,2,2,1,2,10,3,1,1,1,3,5,17,23,9,9,3,3,15,5,
                  4,5,5,5,4,8,1,15,3,3,1,6,3,6,3,4,5,14,4,

0,0,0,0,0,1,1,0,1,1,0,1,1,0,0,1,0,1,0,0,0,1,0,0,0,0,0,0,1,1,0,1,1,1,0,
                  0,0,0,0,0,0,0,0,0,0,0,0,0,0),49,2)


      [,1] [,2]
 [1,]    2    0
 [2,]    2    0
 [3,]   12    0
 [4,]    2    0
 [5,]    1    0
 [6,]   10    1
 [7,]   10    1
 [8,]    4    0
 [9,]   10    1
[10,]    1    1
[11,]    1    0
[12,]    2    1
[13,]    2    1
[14,]    1    0
[15,]    2    0
[16,]   10    1
[17,]    3    0
[18,]    1    1
[19,]    1    0
[20,]    1    0
[21,]    3    0
[22,]    5    1
[23,]   17    0
[24,]   23    0
[25,]    9    0
[26,]    9    0
[27,]    3    0
[28,]    3    0
[29,]   15    1
[30,]    5    1
[31,]    4    0
[32,]    5    1
[33,]    5    1
[34,]    5    1
[35,]    4    0
[36,]    8    0
[37,]    1    0
[38,]   15    0
[39,]    3    0
[40,]    3    0
[41,]    1    0
[42,]    6    0
[43,]    3    0
[44,]    6    0
[45,]    3    0
[46,]    4    0
[47,]    5    0
[48,]   14    0
[49,]    4    0





Q1. Column one is the data set, and column two is an indicator of 1 
and 0. Some values
         in column one corresponding to indicator 1 in column two 
are different, and some
         are the same. There are 5 different groups of values in 
column one with indicator 1
         in column two.

(a) How I can choose only one value (only one observation) from each 
of these groups to
     develop a vector of length 5 as: (1   2    5   10  15).

(b) How I can find number of observations in each of these groups as 
a vector as:
        (2     2    5    4   1).

These are the values with indicator 1.

    [,1] [,2]
 [1,]    1    1
 [2,]    1    1
 [3,]    2    1
 [4,]    2    1
 [5,]    5    1
 [6,]    5    1
 [7,]    5    1
 [8,]    5    1
 [9,]    5    1
[10,]   10    1
[11,]   10    1
[12,]   10    1
[13,]   10    1
[14,]   15    1

=====================





==========================
AbouEl-Makarim Aboueissa, Ph.D.
Assistant Professor of Statistics
Department of Mathematics & Statistics
University of Southern Maine
96 Falmouth Street
P.O. Box 9300
Portland, ME 04104-9300

Tel: (207) 228-8389
Fax: (207) 780-5607
Email: aaboueissa at usm.maine.edu
          aboueiss at yahoo.com
Office: 301C Payson Smith