Use this page to specify the parameters used by the transformer or program.
In the Moving average transformer, you can select one of three statistics:
A simple moving average. A simple moving average (SMA) is defined as:
SMA [row i] = SUM (data values for last N rows) / N
An exponential moving average. An exponential moving average (EMA) is defined as:
EMA [row i] = ( Value [row i] * K ) + ( EMA [row i-1] * ( 1-K ) )
where: K = 2/(N+1)
For example: for a four-day EMA, N = 4, K = 2/5 and 1-K = 3/5
An exponential moving average is also known as an exponentially smoothed moving average.
A rolling sum for N periods of data, where N is specified by the user. A rolling sum (RS) is defined as:
RS [row i] = SUM ( data values for the last N rows)
On the Column Mapping page, map the columns that result from the transformation to columns on your target table.
Columns that result from your transformation are listed on the left side of the page. These columns are named after the selections you made for the Input column, the Statistics column, and the Period column on the Parameters page. For example, if you selected SALARY as the input column, EMA as the calculation, and 7 for the period on the Parameters page, you will see "SALARY_EMA_7" displayed on the left hand side of the Column Mapping page .
Columns in your target table are listed on the right side of the page.
Restrictions:
Because the calculate subtotal transformer can write to its source column, you can map an input column to itself. For example, you can map source column A to itself:
Source Column
Target Column
A
A
You can only map a column to itself as long as the column is not used as an input column in another transformer definition row. For example, you cannot map column A to itself if the following is true:
Source Column
Target Column
A_EMA_7
A_EMA_31
In this example, column A is used as an input column in two separate transformer definitions.
You cannot use a source column that is mapped to target column as a target column in another mapping in this step definition. For example, you have the columns B, C and D. Your first row is specified as follows:
Source Column
Target Column
B
C
Because column B is mapped as a source column, the following mapping is illegal:
Source Column
Target Column
D
B
After a column is mapped as a target, you cannot use the column as either an input column or a target output column in any other mappings in this step definition. For example, you have the following rows
Input Column
Output Column
A
A
B
C
Because you have specified Column A and Column C as output columns, you cannot use them as either input columns or output columns in any additional rows.
These restrictions apply to a single instance of a step. For example, you have step 1 and step 2. In step 1, you can use column B as a source column. In step 2, you can use column B as a target column.