From affaf176e57495ce33adf7659bff865d8122a091 Mon Sep 17 00:00:00 2001
From: "Timur A. Fatkhullin" <amirych@gmail.com>
Date: Thu, 12 Feb 2026 23:31:17 +0300
Subject: [PATCH] ...

---
 CMakeLists.txt             |  23 +++----
 tests/mcc_fitpack_test.cpp | 127 +++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+), 14 deletions(-)
 create mode 100644 tests/mcc_fitpack_test.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 19eab93..5d420fe 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -238,23 +238,15 @@ endif()
 
 add_library(${PROJECT_NAME} INTERFACE ${MCC_SRC})
 target_compile_features(${PROJECT_NAME} INTERFACE cxx_std_23)
+target_include_directories(
+    ${PROJECT_NAME}
+    INTERFACE
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR};>
+        $<INSTALL_INTERFACE:include/${PROJECT_NAME}>
+)
 
 if(USE_ERFA)
     target_link_libraries(${PROJECT_NAME} INTERFACE PkgConfig::ERFALIB)
-    target_include_directories(
-        ${PROJECT_NAME}
-        INTERFACE
-            # $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR};${ERFALIB_INCLUDE_DIRS};${FITPACK_INCLUDE_DIR};>
-            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR};${ERFALIB_INCLUDE_DIRS};>
-            $<INSTALL_INTERFACE:include/${PROJECT_NAME}>
-    )
-else()
-    target_include_directories(
-        ${PROJECT_NAME}
-        INTERFACE
-            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR};>
-            $<INSTALL_INTERFACE:include/${PROJECT_NAME}>
-    )
 endif()
 
 if(USE_BSPLINE_PCM)
@@ -282,6 +274,9 @@ if(BUILD_TESTS)
 
     add_executable(mcc_netmsg_test tests/mcc_netmsg_test.cpp)
     target_link_libraries(mcc_netmsg_test PRIVATE ${PROJECT_NAME})
+
+    add_executable(mcc_fitpack_test tests/mcc_fitpack_test.cpp)
+    target_link_libraries(mcc_fitpack_test PRIVATE ${PROJECT_NAME})
 else()
     # This is just a stub to allow access to the path and library settings for the ${PROJECT_NAME} target during development
     add_executable(just_stub EXCLUDE_FROM_ALL main.cpp)
diff --git a/tests/mcc_fitpack_test.cpp b/tests/mcc_fitpack_test.cpp
new file mode 100644
index 0000000..a1e0916
--- /dev/null
+++ b/tests/mcc_fitpack_test.cpp
@@ -0,0 +1,127 @@
+#include <algorithm>
+#include <functional>
+#include <iostream>
+#include <random>
+#include <ranges>
+
+#include <mcc_bsplines.h>
+
+int main()
+{
+    size_t nt = 30, np = 60, N = nt * np, i = 1;
+    // size_t nt = 10, np = 20, N = nt * np, i = 1;
+    double ts = std::numbers::pi / (nt + 1);
+    double ps = 2.0 * std::numbers::pi / (np + 1);
+
+    std::vector<double> tetha(N), phi(N), func(N);
+
+    auto gen_func = [](double st, size_t& idx) {
+        double v = st * idx;
+        ++idx;
+
+        return v;
+    };
+
+    auto print_func = [](const auto& r, std::string_view name) {
+        std::cout << name << ": ";
+        for (auto& el : r) {
+            std::cout << el << " ";
+        }
+        std::cout << "\n";
+    };
+
+
+    // std::ranges::generate(tetha, std::bind(gen_func, ts, i));
+
+    // i = 1;
+    // std::ranges::generate(phi, std::bind(gen_func, ps, i));
+
+    size_t k = 1;
+    i = 0;
+    for (size_t j = 0; j < nt; ++j) {
+        std::ranges::fill_n(tetha.begin() + i * np, np, ts * (i + 1));
+        std::ranges::generate(phi | std::views::drop(i * np) | std::views::take(np), std::bind(gen_func, ps, k));
+        ++i;
+        k = 1;
+    }
+
+    // std::uniform_real_distribution<double> distr{-0.1, 0.1};
+    std::normal_distribution<double> distr{0.0, 1.0};
+    std::random_device device;
+    std::mt19937 engine{device()};
+
+    std::ranges::generate(func, [ii = 0, &distr, &engine, &tetha, &phi]() mutable {
+        double v = (5.0 + tetha[ii]) * 1.3 + (3.0 + phi[ii]) * 3.1 + distr(engine);
+        ++ii;
+        return v;
+    });
+
+
+    int ntk = 24, npk = 29, nf = (ntk + 4) * (npk + 4);
+    // int ntk = 3, npk = 6, nf = (ntk + 4) * (npk + 4);
+    std::vector<double> tk(ntk + 8), pk(npk + 8), coeffs(nf);
+    ts = std::numbers::pi / (ntk + 1);
+    ps = 2.0 * std::numbers::pi / (npk + 1);
+
+    i = 1;
+    std::ranges::generate(tk | std::views::drop(4) | std::views::take(ntk), std::bind(gen_func, ts, i));
+    i = 1;
+    std::ranges::generate(pk | std::views::drop(4) | std::views::take(npk), std::bind(gen_func, ps, i));
+
+
+    double rs = 0.0;
+    int ec = mcc::bsplines::fitpack_sphere_fit(tetha, phi, func, 1.0, tk, pk, coeffs, rs);
+
+    std::cout << "FIT EC = " << ec << "\n";
+    std::cout << "FIT RESI = " << rs << "\n";
+
+    ntk += 8;
+    npk += 8;
+    std::ranges::fill(tk, -1);
+    std::ranges::fill(pk, -1);
+    ec = mcc::bsplines::fitpack_sphere_smooth(tetha, phi, func, 1.0, 1800.0, ntk, npk, tk, pk, coeffs, rs);
+
+    std::cout << "FIT EC = " << ec << "\n";
+    std::cout << "FIT RESI = " << rs << "\n";
+    std::cout << "NKNOTS: " << ntk << ", " << npk << "\n";
+
+
+    print_func(coeffs, "coeffs");
+
+    // print_func(tetha, "tetha");
+    // print_func(phi, "phi");
+    print_func(tk, "tetha_knots");
+    print_func(pk, "phi_knots");
+    print_func(func, "func");
+
+    std::cout << "\n\n";
+
+    k = 1;
+    ts = std::numbers::pi / (nt + 1);
+    std::ranges::generate_n(tetha.begin(), nt, std::bind(gen_func, ts, k));
+
+    std::vector<double> f_func;
+    tetha.resize(nt);
+    phi.resize(np);
+
+    tk.resize(ntk);
+    pk.resize(npk);
+
+    print_func(tetha, "TETHA:");
+    print_func(phi, "PHI:");
+
+    ec = mcc::bsplines::fitpack_eval_spl2d(tk, pk, coeffs, tetha, phi, f_func);
+    // ec = mcc::bsplines::fitpack_eval_spl2d(pk, tk, coeffs, phi, tetha, f_func);
+    std::cout << "EVAL EC = " << ec << "\n";
+    print_func(f_func, "func");
+
+    std::cout << "\n\n";
+
+    for (size_t l = 0; l < f_func.size(); ++l) {
+        auto r = f_func[l] - func[l];
+        std::cout << r << " ";
+    }
+    std::cout << "\n";
+
+    return 0;
+}