# Calculations

**Window calculations** provide the capability to apply specific computations to measure values and allow you to perform different analytical tasks such as computing running totals, percentages of totals, differences, etc.

To create a window calculation, invoke the Bindings menu and click the required measure. In the invoked Data Item Menu, go to **Calculations** and select one of the available calculations.

After you have selected the required calculation, you can change its default settings by clicking the **Edit** button (the icon).
This invokes the special window containing common and specific calculation settings:

## Percent of Total

A calculation is used to compute a percentage of the total for the specified measure across a window.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
**Expression**displays an expression generated for the current calculation. To change the expression, click**Edit**.

In the Grid below, **Percent of Total** is applied to a fourth column to show a contribution of individual quarterly sales to total sales.

## Running Summary

Can be used to compute a cumulative total for the specified measure across a window.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
**Summary Type**- Specifies a summary function used to apply a calculation.- The
**Expression**displays an expression generated for the current calculation. To change the expression, click**Edit**.

In the Grid below, the **Running Total** is applied to a fourth column to display cumulative sales across all quarters.

## Difference

Can be used to compute the difference between measure values across a window.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
**Target**- Specifies the value used to calculate the difference. The following values are available:*Previous*,*Next*,*First*and*Last*.**Difference Type**- Specifies whether the absolute or percentage difference is calculated.**Expression**displays an expression generated for the current calculation. To change the expression, click**Edit**.

In the Grid below, the **Difference** is applied to a fourth column to show absolute differences between quarterly sales.

## Percentage Difference

A calculation is used to compute the difference in percentages between measure values across a window.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
**Target**- Specifies the value used to calculate the difference. The following values are available:*Previous*,*Next*,*First*and*Last*.**Difference Type**- Specifies whether the absolute or percentage difference is calculated.**Expression**displays an expression generated for the current calculation. To change the expression, click**Edit**.

In the Grid below, **Percentage Difference** is applied to a fourth column to show percentage differences between quarterly sales.

## Moving

The Moving calculation uses neighboring values to calculate a total.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
**Summary Type**- Specifies a summary function used to apply a calculation.**Start Offset**/**End Offset**- Specify start/end offsets from the currently processed value. For instance, if you specified offsets as 1/1, the previous and next values will be used along with the current value to apply the Moving calculation.- The
**Expression**displays an expression generated for the current calculation. To change the expression, click**Edit**.

In the Grid below, a **Moving** calculation is applied to a fourth column to show a moving average across all quarters.

## Rank

Use the Rank calculation to compute rankings for the specified measure across a window.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
**Rank Type**- Specifies the type of ranking. The following ranking types are available:*Unique*,*Competition*,*Dense*,*Modified*and*Percentile*.**Rank Order**- Specifies the order of ranking. You can select*Ascending*or*Descending*.- The
**Expression**displays an expression generated for the current calculation. To change the expression, click**Edit**.

In the Grid below, a **Rank** calculation is applied to a fourth column to show a ranking of sales for individual quarters.

## Custom

Use Custom to specify a custom calculation by adding the required calculation functions inside the measure expression.

**Window Definition**specifies a window that limits measure values participating in a calculation. You can choose between the*Predefined*and*Specific*window definitions.- For the
*Predefined*window definition, you can specify the**Definition mode**that depends on the dashboard item type. - For the
*Specific*window definition, you can manually specify the set of dimensions that fall into the window.

- For the
- The
**Expression**allows you to change the expression for the current measure. To change the expression, click**Edit**.