Force-directed layout that replicates Gephi's Fruchterman-Reingold algorithm. This is a strict port of the Java implementation from Gephi's source code, with additional improvements for reproducibility and flexibility.
layout_gephi_fr(
g,
area = 10000,
gravity = 1,
speed = 1,
niter = 100,
seed = NULL,
initial = NULL,
normalize = TRUE,
gravity_mode = c("linear", "degree", "none"),
cooling_mode = c("constant", "vcf", "linear"),
anchor_strength = 0
)A matrix with x,y coordinates for each node.
An igraph graph object.
Area parameter controlling node spread. Default 10000.
Gravity force pulling nodes toward center. Default 1.0. (Note: Reduced from Gephi's default of 10.0 to prevent circular layouts)
Speed/cooling parameter. Default 1.0.
Number of iterations. Default 100.
Random seed for reproducibility. Default NULL.
Optional initial coordinates (matrix or data frame). Useful for warm-starting or animations.
Logical. If TRUE (default), normalize output to [0,1] range. If FALSE, return raw Gephi-scale coordinates.
Gravity behavior: "linear" (default, standard gravity), "degree" (high-degree nodes feel stronger gravity, creates hub structure), or "none" (no gravity, like igraph FR).
Cooling schedule: "constant" (default, no cooling), "vcf" (Variable Cooling Factor - adapts based on movement), or "linear" (linear decrease over iterations).
Strength of force pulling nodes toward initial positions
(default: 0). Only applies when initial is provided.
This layout is a direct port of Gephi's ForceAtlas algorithm variant of Fruchterman-Reingold. Key differences from igraph's layout_with_fr:
Uses Gephi's specific constants (SPEED_DIVISOR=800, AREA_MULTIPLICATOR=10000)
Includes configurable gravity toward center
Different cooling/speed mechanism
Supports multiple gravity modes for different layout styles