Internal function not to be called by the user
test_null_weights(wgs, specs)
gives an error when wgs is NULL (i.e. non-convergence)
output from 'get_weights()'
list of specifications
Do NOT use this function unless you are ME, a package developer, or a jedi user who really knows what is doing (seriously!)
Internal function. test_weights_output
is called
by plspm
. Basically checks that weights are not
NULL.