ustat_var.lamb_sum.lamb_sum_spec

ustat_var.lamb_sum.lamb_sum_spec(X, C_jjX, C_jkX)

Computes special case bias-corrected product \(\lambda = (\sum_{k \neq i} C_{ik}^X a^X)^2\). This function is used in the family of sampling covariance functions in the ustat_samp_covar submodule. The \(C_{ik}^X\) represent the C-weights, which are computed by the ustat_var.makec() function.

Parameters:

• X (array) – J-by-\(\operatorname{max}(T_j)\) array of teacher mean residuals for a^X

• C_jjX (array) – X’s C-weights for identical teachers (generated using ustat_var.makec() function).

• C_jkX (array) – X’s C-weights for non-identical teachers (generated using ustat_var.makec() function).

Returns:

Array with each row’s/teacher’s bias-corrected product.

Return type:

array