# Tutorial | Window recipe#

The Window recipe utilizes advanced grouping to apply aggregate calculations to each row in your dataset. Let’s practice using different windows to show how they affect these calculations.

## Get started#

### Objectives#

In this tutorial, you will:

• Learn how to configure different windows in the recipe.

• Find cumulative sums for each row.

• Calculate windows based on a range of rows.

• Calculate windows based on a range of values.

### Prerequisites#

To reproduce the steps in this tutorial, you’ll need:

• Basic knowledge of Dataiku (Core Designer level or equivalent).

### Create the project#

1. From the Dataiku Design homepage, click + New Project > DSS tutorials > Advanced Designer > Window Recipe.

2. From the project homepage, click Go to Flow.

Note

You can also download the starter project from this website and import it as a zip file.

You’ll next want to build the Flow.

1. Click Flow Actions at the bottom right of the Flow.

2. Click Build all.

3. Keep the default settings and click Build.

## Create the Window recipe#

We’ll create a Window recipe from the tx_prepared dataset.

1. Select the tx_prepared dataset and click on the Window recipe from the Actions tab.

2. Change the output name to `tx_windows` and click Create Recipe.

## Use an undefined window frame#

Let’s practice first by using an undefined window — that is, one without bounds. In this case, we’ll compute the sum of card purchases by card_id, ordered by purchase_date.

1. In the Window definitions step, toggle on Partitioning Columns.

2. Choose card_id from the dropdown menu.

3. Toggle on Order Columns.

4. Choose purchase_date from the dropdown menu.

5. Toggle on Window Frame, but make no further adjustments.

Next, we’ll choose the correct aggregations for our window.

1. Navigate to the Aggregations step.

2. Enable Sum on the purchase_amount column.

3. Run the recipe.

### Interpret the output#

Now we will interpret the recipe output. For clarity, we’ll also filter the results for a specific card_id since that is the partitioning column.

1. Open the output tx_windows dataset. You’ll see a new column purchase_amount_sum in the dataset.

2. Click the column dropdown header of card_id.

3. Click Filter.

4. Select a frequent card_id value, such as `C_ID_47d2295a52`.

5. For further simplicity, near the top right, click Display > Select displayed columns.

6. Keep only the following columns: id, purchase_date, card_id, purchase_amount, and purchase_amount_sum.

You should see that the purchase_amount_sum is the same for each row! This is because the window frame included all purchase amounts for that credit card in the aggregation.

## Find the cumulative sum#

This next exercise involves finding the cumulative sum of purchase amounts for each row. In this case, we want to find the sum of all purchase amounts of a credit card before and including each purchase date.

1. Click Parent Recipe to reopen the Window recipe.

2. Under the Window Frame settings, select the Limit following rows checkbox and leave the number of rows as `0`. This will set the window to be all rows before and including the current row.

3. Run the recipe and open the output dataset.

Now, the purchase_amount_sum varies for each row. Notice that as the purchase dates increase, the sum also increases. This will be the case if there are no negative purchase amount values, such as for a refund given.

## Use a range of rows#

Now we will set the window to limit the previous rows in addition to the following rows.

1. In the top left corner, click Parent Recipe to reopen the Window recipe.

2. Select the Limit preceding rows checkbox.

3. Set the number of rows before to `5` and the number of rows after to `-1`. This will make the window include five rows before the current row, excluding the current row.

4. Run the recipe and open the output.

In this dataset, the purchase_amount_sum doesn’t necessarily increase with time. This is because the window is not always increasing — after the first five rows in the dataset, it is always five rows in size, leaving out earlier rows from the window frame.

## Use a value range#

So far, we’ve been defining our window relative to the rows in the dataset. However, we can also define the window frame relative to the values in a column. In this case, we’ll be limiting our window frame by a range of days from the purchase_date ordering column.

1. Click Parent Recipe to reopen the Window recipe.

2. Under Window Frame, select Limit window on a value range of the order column.

3. Make the lower bound `5` and the upper bound `-1`.

4. Change the window unit to Days. This will make the window include records that are 5 days before the target row’s date, excluding the target row.

5. Run the recipe and open the output.

This is the first output we’ve seen with empty values after the first row in the purchase_amount_sum column. Why did this happen?

Since we did not use a range of rows for our window, there was no guarantee that there would be any records for the time period before the current record. For example, in the row where the ID equals 7813, the purchase_amount_sum value is empty because there were no purchases from that card for the five days before 2017-01-19.

## Compute lag#

So far, we haven’t changed much in the Aggregations step of the recipe. Let’s try out some different options here.

2. Navigate to the Aggregations step.

3. Under Compute rank for each row, turn on Row number.

4. Under Compute aggregations for each field, enable LagDiff on purchase_date with a value of `1` with the unit Days.

5. Run the recipe and open the output.

First, look at the rownumber column. In this case, we can interpret these values as the count of purchases on this card to date.

Next, look at the purchase_date_lag_diff column. These values show the difference in days between consecutive card purchases. As you can see, even though our window frame is defined by column values, the LagDiff is computed using the previous row (not previous day).

Tip

If we had wanted to rename the columns to better match their meanings, we could have done so in the Output step of the recipe.

## What’s next?#

You just used the Window recipe to enrich your dataset with new insights, while keeping the the structure of the dataset intact.