Hello,
I am trying to simulate bivariate normal data for two groups with different covariance matrix. I need to generate this data for different sample sizes, e.g., sample=20, 40 etc. and 2000 replicates. I want the ratio of sample size in group 1: group 2 to be 1:2.
Below is the code I have for one group. For some reasons, the CREATE statement is creating two separate MVN datasets, and the last datasets overrides the initial one.
Any help will be appreciated.
proc iml; Numsamples=10; /*specify population mean and covariance:grp1*/ mean1={6.0 6.0}; Cov1={0.5280563 0.502445,
0.502445 0.5280563 };
/*specify population mean and covariance:grp2*/ mean2={6.2499 5.7399}; Cov2={0.6280563 0.200978,
0.200978 0.401956 }; call randseed(132); do N=5 to 10 by 5; X=RandNormal(N*Numsamples,Mean2,Cov2); ID=colvec(repeat(T(1:Numsamples),1,N)); Z=ID||X; create MVN from Z[c={"ID" "y0" "y1" }]; append from Z; *end; close MVN; end;
quit;
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