> source("potts.r") > potts(m=2,tmax=1000,beta=0.88) > potts(m=2,tmax=1000,beta=0.89)
Reference to external force. An external force at each site is indicated by where the state 0 implies no external force at a particular site. Entire data of external force is represented in a matrix. To see the external force, use it as initial state
> potts(m=2,tmax=0,init.state=f1) > potts(m=5,tmax=0,init.state=f2)
Explore it. Download potts.r. Choose a different number of common states and inverse temperature , and see how the Gibbs sampler generates a GRF with or without existence of external force.
> source("potts.r") > potts(m=2,tmax=1000,beta=0.9) > potts(m=2,tmax=1000,beta=0.9,ref.state=f1) > potts(m=5,tmax=1000,beta=1.1) > potts(m=5,tmax=1000,beta=1.1,ref.state=f2)
Programming note. An matrix of data a is created with
data.matrix = matrix(data=a, n, m)where the data is a sequence of values, and will be assigned from the first column to the last column of the matrix. For example, a matrix form of Potts state in grid is created and visualized as follows.
> s1 = matrix(data=c(1,2,3,3,1,2,2,3,1,1,2,2,1,1,1,2), 4, 4) > potts(m=3,tmax=0,init.state=s1)
Explore it. Create a matrix of external force, and run the Gibbs sampler for Potts model.
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