Stan compiler bug - bad indices on param names for matrix or array parameters

[mitzimorris]

Summary:

Stan compiler generator generates wrong set of indexes for multi-dimensional parameters. Introduced by #2498, refactor of Stan lang necessary to add tuple types to the Stan language.

Description:

generated c++ code contains methods constrained_param_names and unconstrained_param_names which generate the indexed multi-dim parameter names, e.g.
code:

 if (!include_gqs__ && !include_tparams__) return;
        size_t y_k_0_max__ = N_t;
        size_t y_k_1_max__ = 4;
        for (size_t k_1__ = 0; k_1__ < y_k_1_max__; ++k_1__) {
            for (size_t k_0__ = 0; k_0__ < y_k_0_max__; ++k_0__) {
                param_name_stream__.str(std::string());
                param_name_stream__ << "y" << '.' << k_0__ + 1 << '.' << k_1__ + 1;
                param_names__.push_back(param_name_stream__.str());
            }
        }

results in this output:

y.1.1,y.2.1,y.3.1,y.4.1,y.5.1,y.6.1,y.7.1,y.8.1,y.9.1,y.10.1,y.11.1,y.12.1,y.13.1,y.14.1,y.15.1,y.16.1,y.17.1,y.18.1,y.19.1,y.20.1,y.1.2,y.2.2,y.3.2,y.4.2,y.5.2,y.6.2,y.7.2,y.8.2,y.9.2,y.10.2,y.11.2,y.12.2,y.13.2,y.14.2,y.15.2,y.16.2,y.17.2,y.18.2,y.19.2,y.20.2,y.1.3,y.2.3,y.3.3,y.4.3,y.5.3,y.6.3,y.7.3,y.8.3,y.9.3,y.10.3,y.11.3,y.12.3,y.13.3,y.14.3,y.15.3,y.16.3,y.17.3,y.18.3,y.19.3,y.20.3,y.1.4,y.2.4,y.3.4,y.4.4,y.5.4,y.6.4,y.7.4,y.8.4,y.9.4,y.10.4,y.11.4,y.12.4,y.13.4,y.14.4,y.15.4,y.16.4,y.17.4,y.18.4,y.19.4,y.20.4

Reproducible Steps:

see above example, model src/test/test-models/good/stat_comp_benchmark_models/sir.stan

Current Output:

y.1.1,y.2.1,y.3.1,y.4.1,y.1.2,y.2.2,y.3.2,y.4.2,y.1.3,y.2.3,y.3.3,y.4.3,y.1.4,y.2.4,y.3.4,y.4.4,y.1.5,y.2.5,y.3.5,y.4.5,y.1.6,y.2.6,y.3.6,y.4.6,y.1.7,y.2.7,y.3.7,y.4.7,y.1.8,y.2.8,y.3.8,y.4.8,y.1.9,y.2.9,y.3.9,y.4.9,y.1.10,y.2.10,y.3.10,y.4.10,y.1.11,y.2.11,y.3.11,y.4.11,y.1.12,y.2.12,y.3.12,y.4.12,y.1.13,y.2.13,y.3.13,y.4.13,y.1.14,y.2.14,y.3.14,y.4.14,y.1.15,y.2.15,y.3.15,y.4.15,y.1.16,y.2.16,y.3.16,y.4.16,y.1.17,y.2.17,y.3.17,y.4.17,y.1.18,y.2.18,y.3.18,y.4.18,y.1.19,y.2.19,y.3.19,y.4.19,y.1.20,y.2.20,y.3.20,y.4.20

Expected Output:

output above.

also, repo stat_comp_benchmark contains models, data, and expected results.

Additional Information:

Provide any additional information here.

Current Version:

v2.18.0

[mitzimorris]

fixed by PR #2611