#Merging tables

 Introduction

*easyNet* presents you data in form of tables, which are also called *dataframes*, this name reflecting the *R* software terminology.
Both stimuli files (**Stimuli** tab in **Method** window), and results from running a set of trials (**Tables** tab in **Results** window), are stored and presented in form of tables. 

Often you would like to be able to combine tables together, either to inspect them or to plot their content. *easyNet*  offers you the **merge** operation, which allows you to merge two tables by rows and obtain a new one where matching columns are used to perform the merge. For example, if both a stimuli table and a trial results table contain a column of stimuli (e.g. words) with identical values, you can obtain a merged table with the same number of rows as the original tables and with the columns from both tables. This operation is often a convenient preliminary step to produce a [bar_plot](bar plot).


 Procedure

Click on the **merge** icon at the top of the **Tables** tab in **Results** window (see red arrow below). 

![merge_button.png](merge_button.png)

A dialog form like the one below will pop up. Here you have to select the two dataframes you want to merge, called **x** and **y**, and the column(s) you want to match, called **keys**. Note that in general you can specify a key including more than a column, which is necessary when no single column provides unique values but only a pair or a tuple of column does. Finally you have to specify a name for the newly created dataframe. Once you are done, the merged dataframe will be displayed in the Tables tab. Note that sometimes *easyNet* is able to guess some of the values for you, but you can always change them if you want to.
 ![merge_dialog.png](merge_dialog.png)