Finishing up and starting lu decomp

test/test_transpose.cpp

@@ -0,0 +1,88 @@
+
+#include "test_common.h"
+#include "./utils/utils.h"           // matrix.h, vector.h
+#include "./numerics/transpose.h"    // numerics::transpose / inplace_transpose
+
+using utils::Mi; using utils::Mf; using utils::Md;
+
+//
+// ---------- Out-of-place transpose (rectangular) ----------
+//
+TEST_CASE(Transpose_Rectangular_OutOfPlace) {
+    // A = [ [1, 2, 3],
+    //       [4, 5, 6] ]  (2x3)
+    Md A(2,3,0.0);
+    A(0,0)=1; A(0,1)=2; A(0,2)=3;
+    A(1,0)=4; A(1,1)=5; A(1,2)=6;
+
+    auto AT = numerics::transpose(A);   // (3x2)
+
+    CHECK(AT.rows()==3 && AT.cols()==2, "shape wrong after transpose");
+    CHECK(AT(0,0)==1 && AT(1,0)==2 && AT(2,0)==3, "first column wrong");
+    CHECK(AT(0,1)==4 && AT(1,1)==5 && AT(2,1)==6, "second column wrong");
+
+    // Involution: T(T(A)) == A
+    auto ATT = numerics::transpose(AT);
+    CHECK(ATT == A, "transpose(transpose(A)) != A");
+}
+
+//
+// ---------- In-place transpose (square) ----------
+//
+TEST_CASE(Transpose_Square_InPlace) {
+    // 3x3 with distinct values
+    Mf S(3,3,0.0f);
+    float val = 1.0f;
+    for (uint64_t i=0;i<3;++i)
+        for (uint64_t j=0;j<3;++j)
+            S(i,j) = val++;
+
+    // Make an explicit transpose to compare against
+    auto ST = numerics::transpose(S);
+
+    // In-place should match the out-of-place result
+    numerics::inplace_transpose(S);
+    CHECK(S == ST, "inplace_transpose result mismatch");
+
+    // Involution: applying in-place again should return original
+    numerics::inplace_transpose(S);
+    // Now S should equal the original pre-inplace matrix (which was transposed above)
+    // We can reconstruct original by transposing ST:
+    auto orig = numerics::transpose(ST);
+    CHECK(S == orig, "inplace transpose twice should restore original");
+}
+
+//
+// ---------- In-place transpose must throw on non-square ----------
+//
+TEST_CASE(Transpose_InPlace_Throws_On_Rectangular) {
+    Md R(2,3,0.0);   // rectangular
+    bool threw = false;
+    try {
+        numerics::inplace_transpose(R);
+    } catch (const std::runtime_error&) {
+        threw = true;
+    }
+    CHECK(threw, "inplace_transpose must throw on non-square matrices");
+}
+
+//
+// ---------- Edge cases: 0x0 and 1x1 ----------
+//
+TEST_CASE(Transpose_Edge_0x0_1x1) {
+    // 0x0 should be fine both ways
+    Md E; // 0x0
+    auto ET = numerics::transpose(E);
+    CHECK(ET.rows()==0 && ET.cols()==0, "0x0 transpose shape wrong");
+    // in-place on 0x0 (rows==cols) should not throw
+    numerics::inplace_transpose(E);
+    CHECK(E.rows()==0 && E.cols()==0, "0x0 inplace transpose changed shape");
+
+    // 1x1 should be a no-op and not throw
+    Mi I(1,1,0);
+    I(0,0) = 42;
+    auto IT = numerics::transpose(I);
+    CHECK(IT.rows()==1 && IT.cols()==1 && IT(0,0)==42, "1x1 transpose wrong");
+    numerics::inplace_transpose(I);
+    CHECK(I(0,0)==42, "1x1 inplace transpose changed value");
+}