---
title: "Transforming data"
slug: "transforming-data"
updated: 2024-10-22T06:55:57Z
published: 2024-10-22T06:55:57Z
canonical: "userguide.dataclassroom.com/transforming-data"
---

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

# Transforming data

Sometimes you have some data in a column, and you want to change it in some way. You might want to **multiply it by a number**, take a **square root** - whatever.

With the column transform feature, you can apply a function to all the data in the column at once, creating either:

- A new set of values in the same column
- A new column to the right of the original one

To do this, click the **column transform button** on the column header:

![](https://cdn.document360.io/62f8f41e-e041-42c4-b9bc-8ae1eb45d064/Images/Documentation/image-1620803945087.png)

You can then choose between **replacing the data** in this column, or **creating a new column**.

Don't see the button?This is an advanced feature, and the button may not be shown. See [Customizing controls](/v1/docs/customizing-which-controls-are-shown) for how to get the button to show.

You then get to specify the function, and the new column name (if relevant):

![](https://cdn.document360.io/62f8f41e-e041-42c4-b9bc-8ae1eb45d064/Images/Documentation/image-1620804327170.png)

### Available functions

Here is a list of the available transform functions.

- Y represents the value in the original column
- K is an optional value, required for some of the transforms. For example to convert 'Year' to 'Age' you might do **Negate (k - y)** and have a constant k = 2024.
- K can also be taken from another column, so you can e.g. multiply two columns together.

| Function | Description |
| --- | --- |
| Add (y + k) | Add a number (k) to each value (y) |
| Subtract (y - k) | Subtract a number (k) from each value (y) |
| Multiply (y × k) | Multiply y by k |
| Divide (y ÷ k) | Divide y by k |
| Negate (k - y) | Subtract k from y (If k = 0, this is inverting the sign of y) |
| Invert (1 ÷ y) | Invert y |
| K divided by y (k ÷ y) | Divide y into k |
| Absolute value - abs(y) | Make y values always positive |
| Square (y2) | Square of y |
| Square root (√y ) | Square root of y |
| Power (yk ) | Raise y to the power of k |
| Log base 10 (log10 y ) | Base 10 logarithm of y |
| Log base e (log10 y ) | Base e logarithm of y (natural logarithm) |
| Exponent (ey ) | Raise e to the power y |
| Round (rnd) | Round to K digits after decimal point |
| Precision (prec) | Round to K significant digits of precision |
| Ranking - rank(y) | Rank values in column numerically and replace with a number representing their order in the ranking. Equal values get the same ranking. |

Need a function we don't support?Just let us know at [help@dataclassroom.com](mailto:help@dataclassroom.com). We add features all the time based on input from our users.

### Functions of two columns

This is done by specifying **K as coming from another column**, as in this simple example:

![](https://cdn.document360.io/62f8f41e-e041-42c4-b9bc-8ae1eb45d064/Images/Documentation/image-1729510420802.png)

### Multiple transforms

You can create a sequence of transforms, if your data require this. For example, you could:

- First transform the number with a multiply or divide (convert inches into metres)
- Then take the square of that result (metres into square metres for area)

### Errors

Some of these mathematical functions cannot handle all possible input values. For example:

- You can't take the square root of a negative number
- You can't take the logarithm of zero
- You can't divide anything by zero (OK you can, but you get "infinity" as the result!)

These errors will be flagged and you will get a warning if you are trying to apply an "impossible" transform.

### Differentiation (slopes)

We don't currently have a function to differentiate column values (it's on the roadmap) but you can achieve the same (or similar) result by making a graph with a **regression line**, and then adding slope markers which give you the **slope of the line at each point**. You can then create a new column of data from these slope values. See [this article on slopes and residuals](/v1/docs/slope-of-the-line-differential) for how to do this.