How to calculate entropy change?

The formula for Entropy change is sum (xij*log2 (xij)). To calculate entropy change in Excel follow the steps below.

We are going to use dummy data. Suppose you have the following data.

data table


Before calculating the entropy change you first have to find out the sum of each series. Click on Cell A5 and write this formula =SUM (A2:A4). Select cell A and move cursor to the bottom right of the cell, a black plus sign will appear, drag the plus sign to cell C5 to copy the formula in these cell.

entropy sum

Now click on cell A6 and write the formula =LOG (A5, 2)

Select Cell A6 and bring your cursor to the bottom right of the cell. A black plus sign will appear. Now drag the black plus sign to Cell C6 to copy formula in these cell. Hats it, you have now calculated entropy change in Excel.

log entropy