# Install package "jmv" if not already installed
install.packages("jmv")
# Load data that is also used in jamovi
load("INSERT_PATH_TO_DATA_HERE")
# This is the code from jamovi
# The jmv:: notations means that it is using the "jmv" package
jmv::descriptives(
formula = RPM7 ~ Caffeine:MouseType,
data = X, # Make sure to change the data name. Here I use "X"
desc = "rows",
hist = TRUE,
bar = TRUE,
box = TRUE,
dot = TRUE)2 jamovi - a statistical spreadsheet
Learning objectives
The learning objectives for this theme is to:
- Understand that jamovi is a software for statistical analysis built on R code.
- Be able to import and manipulate data in jamovi.
- Be able to translate between R and jamovi using code produced in jamovi.
2.1 Material
Below is some material for you to install and learn how to use jamovi.
2.2 Introduction to jamovi - in short
jamovi is a statistical spreadsheet based on R. It is useful for doing statistical analysis without the need to write code. However, it does also come with some limitaitons, and many will find that it is not nearly as flexible as R. So while it is a great tool for statistics, it does not void the benefit of learning to code.
In jamovi it is possible to:
- Import and manipulate data.
- This includes filtering of existing variables and creating new variables by transformation of existing ones.
- Create tables of descriptive statistics with accompanying plots.
- This includes tables of mean, median, mode, variance and so on.
- The plots include histograms, boxplots, violinplots, qq-plots etc.
- Do inferential statistics.
- Such as t-test, ANOVA, and chi-squared tests.
- Work with latent variable models.
- Such as PCA.
All of this will end up in a report created by jamovi. In this report it is possible to add text as well as export results for use in other software.
jamovi uses R code
It is important to note that jamovi uses R-based code behind the scenes. Most of jamovi’s outputs are based on the jmv package which can be installed and run in R.
2.2.1 Importing data
To open a dataset in jamovi:
- Click on the -menu in the upperleft corner.
- Click “Open” and choose a the data file you want to import.
- jamovi will now open the file in a new instance.
The video below describes how to import and manipulate data in jamovi.
2.2.2 Analyzing data
To analyze a dataset in jamovi:
- Navigative the the “Analyses” tab.
- Click on the type of analysis you need.
- Such as Explorative, T-Tests, ANOVA, Regression and so on.
- A window will open on the left hand side making it possible to add variables to the analysis.
- The report on the right hand side will now include results and plots of your choosing.
The video below describes how to analyze data in jamovi.
Installing modules in jamovi
It is possible to install packages - called modules - in jamovi to get more functionality:
- Click on the “Modules” plus-sign in the upper right corner.
- Choose “jamovi library”.
- A window will open where you can add modules to your current installation of jamovi.
2.2.3 Create computed variables
It is possible to create new variables from excisting variables in jamovi - so called computed variables:
- Navigate to the “Variables” tab.
- Click “Add” and choose wether to insert a transformed or computed variable.
- Choose the function you want to ue for computing the new variable.
- This can be filter functions as well as mathematical transformations.
The video below describes how to create computed variables in jamovi.
2.2.4 Extraction R code from jamovi
As mentioned, jamovi calls R code in the background. It is possible to extract this code and run it directly in R.
- Create some sort of analysis.
- Click on the three dots in the upper right corner and put a check mark in “Syntax mode”.
- You will now see code for each analysis that you can copy and insert directly into R.
- Make sure that you have installed the packages and loaded the data before running the call in R - see the example below.
- Sometimes the data variable name is different in R than in jamovi - make sure you update the code accordingly.
The video below describes how to extract R code from jamovi.
A short example
The code below has been constructed from the code generated by jamovi as well as a few function written in R. It generates a descriptive table as well as a few plots.
The namespace operator
The :: notation - called the namespace operator - in R indicates that the descriptives function is a part of the jmv package. It is a way to call functions from a specific package without having to load the entire package using library(jmv).
The namespace operator can also be used with other packages, for example readxl::read_excel().
The code above returns a very pretty descriptive table as well as a histogram, a barchart, and a boxplot with jittered dots. All the plots can be viewed using the navigator arrows in the Rstudio plot viewer.