---
title: "PostFunction"
slug: "delta-percent"
updated: 2022-11-08T13:16:08Z
published: 2022-11-08T13:16:08Z
canonical: "docs.datajet.app/delta-percent"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.datajet.app/llms.txt
> Use this file to discover all available pages before exploring further.

# delta(percent)

## PostFunction: [delta%]

### Returns the change between rows as a percentage of the total change between the first and last rows in the result-table.

1. Calculates the difference between current row and previous row *(deltaX)*
2. Calculates the total change between the last row in the data set and the first row in the data set (*TotalChange*)
3. Divides the difference for current row by the total change *(deltaX / TotalChange)*

## Purpose

Use this function to:

- See change as a percentage of overall change from first row to last row
- Calculate percentage change contribution for each reporting per

## Calculation

```actionscript
Delta% = Delta(X) / TotalChange

Row(N) = "value for last row in resultset"
Row(0) = "value for first row in resultset"
Row(X) = "value for current row"
Row(X-1) = "value for previous row"
Delta(X) = Row(X) - Row(X-1)
TotalChange = Row(N) - Row(0)
```

## Sample Result

![deltapercent_sample](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/deltapercent_sample.PNG)

## Parameters

| Input | Description |
| --- | --- |
| **Dimensions** | Discrete field(s). All fields must come from the same table. |
| **Name** | Name to be displayed as Column Header in result grid |
| **Measure** | The field to be used in the post-function calculation. Must be numeric if Function is anything other than COUNT. Must come from same table as DIMENSIONS. Supports Discrete or Continuous DataTypes. |
| **Function** | COUNT / SUM / AVG / MIN / MAX / STDEV |
| **Post** | **delta** |
| ***Value*** | Optional. Filter to apply when evaluating FUNCTION. Only records in the Filter Recordset will be included in the Function and Post-Function calculations. Must come from same table as DIMENSION/MEASURE or be linked to the Dimension table. |
| ***Axis*** | 0 / 1. Y-Axis to use when plotting graph. Default = 0 |
| ***Plot*** | Y / N. Specifies whether measure’s output column should be plotted on graph. Default = Y |
| ***Resolve*** | Optional. Resolve level for the measure. If blank, Resolve = Dimension Table |
| ***Series Type*** | Default / Bar / Stacked Bar / Line / Spline / RangeLow / RangeHigh / CSLow / CSHigh / CSOpen / CSClose Determines the graph style for the measure. |
| ***Popup*** | Default / None / Extended |
| ***Prefix*** | $ / £ / E / % |

## Usage Notes

1. Calculates the difference between current row and previous row *(deltaX)*
2. Calculates the total change between the last row in the data set and the first row in the data set (*TotalChange*)
3. Divides the difference for current row by the total change *(deltaX / TotalChange)*

## Example

Calculate monthly sales growth as a percentage of total change over the period.

NoteMeasure 1 is included purely for illustration. It is not necessary to include this measure for the calculation to work

| Dimension(s): | [Transactions].[YearMonth] |
| --- | --- |
| Measure 1 | - Name: =Sales This Month - Measure: = transactions.castprice - Function: =sum - Post: = - Value: = | - Axis: =0 - Plot:=Y - Resolve:= - Series Type:=Default - Popup:=Default - Prefix:= |
| Measure 2 | - Name: =Monthly Change - Measure: =transactions.castprice - Function: =sum - **Post: =delta%** - Value: = | - Axis: =0 - Plot:=Y - Resolve:= - Series Type:=Default - Popup:=Default - Prefix:= |

![deltapercent_example1](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/deltapercent_example1.png)

![deltapercent_example2](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/deltapercent_example2.png)

Here we can see that the period [200009 to 200010] had **17.83%** of the **total growth over the period.**

### See Also:

- [Engineering](/v1/docs/engineering)
- [Post Functions - Overview](/v1/docs/post-functions-overview)
- [delta](/v1/docs/postfunction-delta)