Sampling
Create a table with data sampled from another table.
Sampling allows you to pick data from a source table (population) to fill a target table. The sampling can be random or in a periodic basis, as well as with or without sample replacement in the source table.
Sampling is done row-wise. That means, the sampled data will pick the whole line of the source table and copy into a line of the target table.
Sampling Method
Random
Picks exactly Sample Size lines of the source table in a random way.
Sample size
Number of lines sampled from the source table. The Sample size is limited to the population size for all sampling methods without replacement.
With replacement
When checked, put back samples in population (source table) after draw. A sample can be drawn more than once and therefore a larger sample size than population is possible. This option is mutually exclusive with Keep order. When unchecked, a sample drawn is not put back to the population and sample size is limited to population size.
Keep order
When checked, samples are drawn in order of population data. Samples are not put back to the population (exclusive with With replacement). This option is automatically checked for Periodic sampling. When unchecked, samples are drawn in random order.
Periodic
Picks lines in a pace defined by Period.
Period
The number of lines to skip periodically when sampling. The Period is limited to the population size.
The following data will be used as example of source data table for sampling:
|
A |
B |
C |
|
|---|---|---|---|
|
1 |
11 |
21 |
31 |
|
2 |
12 |
22 |
32 |
|
3 |
13 |
23 |
33 |
|
4 |
14 |
24 |
34 |
|
5 |
15 |
25 |
35 |
|
6 |
16 |
26 |
36 |
|
7 |
17 |
27 |
37 |
|
8 |
18 |
28 |
38 |
|
9 |
19 |
29 |
39 |
Sampling with a period of 2 will result in the following table:
|
12 |
22 |
32 |
|
14 |
24 |
34 |
|
16 |
26 |
36 |
|
18 |
28 |
38 |