# How to calculate in added columns

When creating a chart, you have the option to **add a column **in step 2: Check & Describe:

Added columns are perfect to ** perform calculations on your uploaded columns**. For example, you can sum up numbers, create conditions, or trim text. In this example, we multiply the data from two columns with each other and name this new column "GDP":

This article explains which expressions are allowed. They will remind you of Excel, LibreOffice or Google Sheets formulae – and you're right, we took some inspiration. You can also always prepare the final data before uploading it to Datawrapper.

At the end of the article, you find a few more examples to give you a better understanding of what's possible.

## Values

You can use the following values in your formulae:

- numbers, e.g.
`3`

or`3.14`

- text, e.g.
`"quick brown fox"`

- column names, e.g.
`gpd_per_capita`

## Expressions for numbers

Expression | Explanation | Example |
---|---|---|

+ - * / % ^ |
simple math operators (use parentheses for grouping) | `value ^ 2` or `(value + 3) * 5` |

ABS |
absolute number | `ABS(value)` or `ABS value` |

SQRT |
square root | `SQRT(value)` or `SQRT value` |

SIN, COS, TAN, ASIN, ACOS, ATAN |
trigonometric functions | `COS(value)` |

LOG, LOG2, LN, LOG10, LOG1P |
logarithmic functions | `LOG10(value)` |

MIN, MAX |
minimum / maximum | `MAX(value, foo, 42)` |

ATAN2 |
calculate angle (Wikipedia) | `ATAN2(y, x)` |

SIGN |
sign of number; returns 1 if number is positive, -1 if number is negative | `SIGN(value)` |

ROUND |
round number to decimal | `ROUND(value)` or `ROUND(value, decimals)` |

FLOOR, CEIL, TRUNC |
other ways of rounding | `FLOOR(value)` |

PI, E |
constants | ` PI * value` |

NUMBER |
convert text to number | `NUMBER(text)` or `NUMBER text` |

RANDOM |
generate a random real number between 0 and 1 when used without arguments, or between 0 and the passed number | `RANDOM()` or `RANDOM(10)` |

## Expressions for text

Expression | Explanation | Example |
---|---|---|

LENGTH |
length of a text | `LENGTH name` or `LENGTH(name)` |

TRIM |
remove whitespace from the beginning and end of text | `TRIM(name)` or `TRIM name` |

SUBSTR |
extract substring from text | `SUBSTR(name, start, length)` |

CONCAT |
concatenate multiple texts | `CONCAT(firstname, " ", lastname)` |

SPLIT |
split text into parts by a substring |
`SPLIT(name, " ")` |

JOIN |
join parts back into text with a substring |
`JOIN(parts, " ")` |

REPLACE |
replace the first occurrence of substring in text | `REPLACE(country, "United States", "USA")` |

TEXT |
convert number to text | `TEXT(value)` or `TEXT value` |

## Expressions for dates

Expression | Explanation | Example |
---|---|---|

DATE |
get current date; or create date from passed year, month and day values (the month parameter is interpreted as 1 = January, 2 = February...); or create date from date as text |
`DATE()` or `DATE(2020, 5, 1)` or `DATE(text)` |

YEAR |
extract year from date | `YEAR(date)` |

MONTH |
extract month from date (1 = January, 2 = February...) | `MONTH(date)` |

DAY |
extract day of the month from date | `DAY(date)` |

HOURS |
extract hours from datetime | `HOURS(date)` |

MINUTES |
extract minutes from datetime | `MINUTES(date)` |

SECONDS |
extract seconds from datetime | `SECONDS(date)` |

WEEKDAY |
day of the week (0 = Sunday, 1 = Monday...) | `WEEKDAY(date)` |

DATEDIFF |
calculate number of days between two dates |
`DATEDIFF(first_date, second_date)` |

TIMEDIFF |
calculate number of seconds between two dates |
`TIMEDIFF(first_date, second_date)` |

## Logical expressions

Expression | Explanation | Example |
---|---|---|

IF |
if-else statement | `IF(condition, yay, nay)` or `condition ? yay : nay` |

NOT, ! |
invert expression | `NOT(condition)` or `NOT condition` or `!condition` |

and |
logical and | `condition1 and condition2` |

or |
logical or | `condition1 or condition2` |

>, <, ==, <=, >=, != |
comparisons | |

in |
check if a substring is included in text; or check if a value is included in parts created by `SPLIT` |
`"John" in name` or `"John" in parts` |

ROWNUMBER |
current rownumber, starting at 0 | `ROWNUMBER` → 0, 1, 2, ... |

## Aggregations

Each number column comes with aggregation values written like this: columnname_aggregation. For example, to get a column with the minimum value of your column "percent_change", insert "percent_change__min" into the formula field:

You can also calculate with these values. Here's an overview of all available aggregations:

Aggregation | Explanation | Example |

__min |
returns the minimum value in the column | `gdp__min` |

__max |
returns the maximum value in the column |
`gdp__max` |

__sum |
returns the sum of all values in the column | `gdp__sum` |

__mean |
returns the mean (= average) of all values in the column | `gdp__mean` |

__median |
returns the median of all values in the column | `gdp__median` |

IF(salary > salary__mean, "earns more than the average", "earns less than the average")

DATEDIFF(date__min, date)

Let's look at some more examples of how to use these expressions:

## Example 1: "pos./neg." with IF

Let's say you have a table with percentage changes, like -5% or +100%. It's sufficient for your reader to know if the change is positive or negative, so you want to print a column that says "pos." or "neg." depending on the change. To do so, add a new column and use the following formula:

IF(percent_change > 0, "pos.", "neg.")

## Example 2: Line breaks with JOIN/SPLIT

Let's say you uploaded a column with country names. For your tooltips, you want more line breaks in your long country names. Add a new column and insert the following formula:

JOIN(SPLIT(country, " "), "<br/>")

Note that we can't use the expression `REPLACE`

here, because it only replaces the first occurance of the substring.

## Example 3: First names with SPLIT

SPLIT is also a good way to just get the first (second, third, etc.) words when you have multiple ones. Let's say you upload a list of the first and last names of The Beatles, but you just want their first names. Try the following formula:

(SPLIT(the_beatles, " "))[0]

This will take the first word (that's a position zero) of your split words:

## Example 4: Jitter with RANDOM()

Let's say you upload a dataset with chocolate rated with grades from 1-10. You want to display it on a scatterplot, but all the chocolates would then lay exactly on top of each other. (We wrote about this problem in this blog post.) It's time to introduce some jitter. To do so, use the following formula:

rating + (RANDOM() / 4) - 0.125

This divides a random number between 0 and 1 (e.g. 0.4) by 4 (→ 0.1) and then subtracts 0.125 (→ -0.025):