# dimensionalize (previously exact_grains)

> AQL Syntax: always evaluate an expression using certain grains; Dimensionalized Measure

:::info
We have renamed `exact_grains` to `dimensionalize` to align with how the function is used in practice. 
While we will continue to support `exact_grains` for backward compatibility, please use `dimensionalize` to ensure that your code is readable.
:::

## Definition
Evaluate an expression using a specific Level of Detail (LoD) context, regardless of the outer context. You can use `dimensionalize` for use cases like [dimensionalized measure](/as-code/aql/cookbook/level-of-detail#use-case-2-fixed-lod--dimensionalize) and [cohort analysis](/as-code/aql/cookbook/aql-cohort-retention).

:::caution
This is only allowed in the definition of a Dimension, and not elsewhere.
:::

**Syntax**

```aml
dimensionalize(measure, dimension, ...)
```

```aml title="Examples"
dimension order_value {
  description: "Total order value of this user"
  definition: @aql dimensionalize(sum(order_items.order_value), users.id) ;;
}

// with pipe
dimension order_value {
  description: "Total order value of this user"
  definition: @aql sum(order_items.order_value) | dimensionalize(users.id) ;;
}
```

**Input**

- `measure`: A measure that you want to evaluate against a specific LoD context.
- `dimension` (**repeatable**): A dimension that you want to use as the LoD context.

**Output**

A new dimension 

---
## Sample Usages
The following example creates a dimension `customer_lifetime_value`, by dimensonalizing the measure total sales 
```aml
dimension customer_lifetime_value {
  ...
  definition: @aql sum(orders.amount) | dimensionalize(users.id) ;;
} 
```
Total orders *amount* of this *user* equal to *customer lifetime value* field

  

We can also reuse this dimension just like other dimension to derive further analytics insight. Let's define `average_customer_lifetime_value` metric 

```aml
metric average_customer_value {
  ...
  definition: @aql  average(users.customer_lifetime_value) ;;
}
```

Using the above metric to find Average Customer Lifetime Value per Continent

  

## See also

- [`of_all()`](/reference/aql/of_all)
- [`keep()`](/reference/aql/keep)
- [Level of Detail](/as-code/aql/learn/level-of-detail)
- [Order of Operations](/as-code/aql/order-of-operations)