Stan

data {

int<lower=0> N;

real[N] x;

real[N] y;

real[N] y_err;

}

parameters {

real a;

real b;

real c;

real d;

}

model {

for (i in 1:N) {

real m;

m <- a*sin(x[i]*b + c) + d;

y[i] ~ normal(m, y_err[i]);

}

}

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