BeckmannDistribution
BeckmannDistribution[μ1,μ2,σ1,σ2] represents the Beckmann distribution with means μ1 and μ2 and standard deviations σ1 and σ2.
BeckmannDistribution[μ1,μ2,σ1,σ2,ρ] represents the Beckmann distribution with means μ1 and μ2, standard deviations σ1 and σ2, and correlation ρ.
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