Gephi Tutorial: How to Import Data into Gephi

Gephi focus on data import

V 1.2 Sept 2014

Clment Levallois Gephi Support Team and Assist. Prof. @EMLYON

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Clement Levallois 2

Bio notes

Education in economics, management, history of science (Ph.D.) Turned to digital methods for research.

data visualization, network analysis, natural language processing, web applications and more.

Member of the Gephi Community Support team Gephi certified trainer https://marketplace.gephi.org/service/data-analysis/

Contact, feedback welcome: on twitter @seinecle or

www.clementlevallois.net

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1. Network already formed

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Network already formed? Import is direct

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Network data in Excel format

- Via the data laboratory

- Needs at least a list of edges

- If you dont have a list of nodes, they will be created automatically fro the nodes mentioned in the edges list - just tick the option for nodes creation when prompted in the edge import wizzard!

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Frequent mistakes when importing data in the data lab:

- Take extra caution with the headers (first line) of your files! At least: - For edges: Source,Target - For nodes: Id,Label

- Take extra caution with the format of fields!

- Check that your numeric attributes (as opposed to textual) are not imported as String (which means text), but as numbers indeed (Float, Double or Integer)

- If you import a list of nodes and edges

- Import the list of nodes first!

- If you import a list of edges only - Check that the option for the creation of missing nodes is selected

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2. Data not in network format yet

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The general idea

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The steps YOU START WITH

List / table of observations

1. Extract connected entities (a network!)

2. Format this network in a conventional standard

3. Display the network with a software package / in the

browser

Not many solutions!

Many solutions

Many solutions

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Gaze: similarity computer

Network connecting universities, with weak or strong ties depending on the similarity in terms of journals where these univ. publish

Gaze can be downloaded from www.clementlevallois.net

Available soon as a Gephi plugin (easier to use, works on Macs) Contact me at [email protected] if you need it now.


Creating a network from co-occurrences data in Excel / CSV

Network made of authors and literary agents

Network of article co-authors

Network formed by co-authors and the journals where they publish

A plugin to install directly from Gephi (Tools -> Plugins)

See next slides for further instructions on how to use this plugin


1. Install the Plugin 1. Tools -> Plugin

2. Select Convert Excel and csv files in the tab Available plugins, then install it and restart Gephi


2. Select Import Spigot, then Data importer and follow the wizzard


Example of a dataset

This Excel file can be converted into a network where: - Followers are connected to followers - Followers are connected to persons being followed - Time periods are taken into account. Note on proper formats for the Date column: - Can be an interval of dates, with the start date and end date separated by a comma (like above) - Can be an interval of years, also separated by a comma (2012,2014) - Can be a simple date (2012-12-12) or simple year (1979)


Create a dynamic network via the data laboratory

Need two attributes for the nodes: An attribute containing the apparition date for the nodes Another one for the disappearance date for the nodes

Use the fusion function to create a time interval from these 2 attributes

(see next slide)

Same principle to create dynamic edges.

This approach has severe limits: only the topology of the network is dynamic, not the attributes (which stay fixed). And the dynamic topology is very limited a node can just appear and disappearm thats all.

This is a case where a programmatic approach would bring much more flexibility.


The function Merge columns

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2. Select the 2 columns which contain the dates of beginning and end (date or simple number, works as well)

3. Select Create time interval

Click on this button


Last step: create time interval

It is possible to leave the end date empty.

If your temporal data are in the format of a date, be cautious to register the correct format, failing to do so will crash the creation and probably need you to restart Gephi to re-initialize.

Thats all! You can then switch to the Overview, activate the timeline and animate the network


Next step: Gephi advanced functions

Slide Number 1Bio notes1. Network already formedNetwork already formed?Import is directNetwork data in Excel formatFrequent mistakeswhen importing data in the data lab:2. Data not in network format yetThe general ideaThe stepsGaze: similarity computerCreating a network from co-occurrences data in Excel / CSV1. Install the Plugin2. Select Import Spigot, then Data importer and follow the wizzardExample of a datasetCreate a dynamic networkvia the data laboratoryThe function Merge columnsLast step: create time intervalNext step:Gephi advanced functions

Documents

Gephi Tutorial: How to Import Data into Gephi