Vernier Software & Technology

# How to Set Up a Calculated Column

Creating a calculated column in Logger Pro allows you display extra information during data collection or extend your analysis afterward. Calculated columns are data created by performing mathematical operations on existing data columns. For example, you can create a "Kinetic Energy" column by using the velocity data column.

Today I'm going to show you how to create Calculated Column in Logger Pro. You can create a calculated column either before or after collecting data, to be able to see extra information during data collection or as part of your analysis afterwards.

In my example here, you can see that I've already collected some position, velocity, and acceleration data from our motion and coder system. I'm interested in seeing how the kinetic energy thing coder cart changed during the motion. My calculated column makes this possible.

To create a calculated column, go to the data menu and select a new calculated column. In this dialog box, we fill in the information about the kind of calculation we'd like to do. In name, I'll place, call this Kinetic Energy. Give it a short name of just EK. Units of joules. Notice for each of these text boxes, I can select Greek letters, subscripts so on and so forth. I want to include this calculated column in my current data set. If you have multiple data sets, you can select them from this drop down menu. If you'd like to add them to all of your data sets, you can click this box here. In the expression field, I'll enter the calculation that I'd like to perform.

Kinetic Energy is simply one half times the mass, in this case 570 grams, times the square of the velocity. Now the velocity is a quantity that we've measured and as such it's in one of our columns. These are the variables that you enter into your expression.

There are several functions already built into Logger Pro that you have access to. For instance, derivatives and integrals. Likewise, if you define any user parameters in your Logger Pro experiment file, you can access them from this drop down menu. I went and entered the final piece of my equation here. Velocity squared and hit done. You can see that new column was added to my data table, Kinetic Energy.

For each of the times, the kinetic energy has been calculated by multiplying one half times the mass, times the velocity. The value of the velocity on the column here. I can display this data just like any other column of data. Creating a Calculated Column is a great way to extend your lab activities and add a layer of analysis.