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Description

Returns the base-e logarithm of the selected number. Optionally, you can add a second argument to calculate the log base x of a given number.

How does it work in the search window?

Select Create column in the search window toolbar, then select the Logarithm: natural / arbitrary base operation. You need to specify at least one argument:

Argument

Data type

Argument mandatory

integer, float

Base

integer, float

The data type of the values in the new column is float.


Example


We want to get the base-e logarithm of the numbers in our posNumbers1 column. To do it, we will create a new column using the Logarithm: natural / arbitrary base operation.

First, we must transform the string values in the posNumbers1 column into a data type integer. To do it, create a new column using the To Int operation. Call the new column integerValues

Now, create another column using the Logarithm: natural / arbitrary base operation. The arguments needed to create the new column are:

  • Argument integerValues column

Click Create column and you will see the following result:

How does it work in LINQ?

Use the operator select... as...  and add the operation syntax to create the new column. This is the syntax for the Logarithm: natural / arbitrary base operation:

  • log(number)

  • log(base_number, number)

Example

You can copy the following LINQ script and try the above example on the my.upload.sample.data table.

from my.upload.sample.data
select split(message, ";", 17) as posNumbers1
select int(posNumbers1) as integerValues
  select log(integerValues) as loge
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