[R] descriptive statistics qn

Sibusiso Moyo smoyo at vt.edu
Tue Oct 20 18:04:40 CEST 2009

```This is day one on R for me, I am trying to figure out how to do simple
computations. For example I have a data set with 200 observations. I am
trying to compute the mean and variance in r for 1:25 (first 25
observations); 1:50 (first 50 obs) ; 1:100th observation etc. Here  is the
dataset:

Id value
1 2.2338
2 3.13597
3 1.98685
4 4.35593
5 2.43963
6 4.20262
7 3.12131
8 4.79583
9 3.13937
10 3.47266
11 3.79954
12 4.32285
13 3.00058
14 1.26102
15 4.07329
16 3.42037
17 1.99195
18 5.4461
19 3.03448
2 2.63395
21 0.99851
22
4.59577
23
2.77719
24
4.82748
25
4.11373
26
2.38615
27
1.81247
28
0.920195
29
2.78129
30
3.10531
31
3.60793
32
1.66597
33
4.80673
34
4.80266
35
5.35791
36
2.44573
37
2.63854
38
4.13737
39
1.68496
40
3.86962
41
1.60028
42
4.35621
43
3.60847
44
2.38884
45
1.03786
46
5.48904
47
1.95086
48
2.75401
49
2.25081
50
3.46435
51
0.309484
52
2.49405
53
4.52522
54
1.17947
55
2.50136
56
1.74537
57
5.48072
58
1.81081
59
2.67793
60
4.40603
61
3.21767
62
2.68124
63
1.9723
64
1.25973
65
2.64177
66
3.28414
67
3.2394
68
4.07508
69
2.32812
70
3.42763
71
2.40944
72
2.43776
73
0.072419
74
6.29773
75
2.29704
76
6.07705
77
1.59146
78
4.74327
79
5.29088
80
4.17874
81
1.80639
82
3.70503
83
3.13294
84
5.44017
85
3.50002
86
2.1762
87
2.27356
88
4.45687
89
1.99272
90
3.74362
91
3.89474
92
0.93481
93
4.99464
94
1.02872
95
2.63587
96
3.85226
97
4.82513
98
1.1171
99
1.09368
100
3.91599
101
3.91832
102
1.81166
103
1.48144
104
5.24373
105
3.15134
106
3.03343
107
3.373
108
6.10409
109
4.84878
110
1.95195
111
2.25949
112
1.45546
113
3.60767
114
3.10228
115
3.22694
116
0.861855
117
3.93392
118
2.81212
119
1.62434
120
2.41149
121
4.42936
122
2.4765
123
0.979153
124
3.3482
125
1.20345
126
1.56576
127
5.1418
128
3.5585
129
3.21124
130
3.52901
131
2.38191
132
3.6129
133
3.56378
134
2.70181
135
0.355836
136
3.10734
137
6.22159
138
4.7172
139
2.88295
140
2.87566
141
2.01538
142
2.78835
143
2.26519
144
1.38217
145
2.63885
146
1.0584
147
1.93247
148
3.10316
149
2.24714
150
5.08326
151
2.21789
152
4.63046
153
3.90057
154
2.19171
155
5.46094
156
1.84918
157
1.04059
158
4.57513
159
5.06956
160
3.65212
161
1.14078
162
5.89406
163
2.86261
164
1.87261
165
4.47285
166
3.13892
167
1.59146
168
1.07166
169
2.82925
170
2.83742
171
5.13528
172
3.20376
173
1.56253
174
3.08726
175
3.52339
176
3.66837
177
2.70302
178
2.00471
179
3.6823
180
2.90728
181
2.39302
182
2.54367
183
3.98498
184
4.17124
185
1.99922
186
2.61908
187
2.24057
188
3.29836
189
2.59912
190
4.49458
191
1.44657
192
2.99004
193
5.15769
194
2.64342
195
1.81755
196
5.1977
197
4.10043
198
4.63281
199
3.20347
200
2.08211

```