initial commit

.gitignore

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+# Local files
+.env
+*.local*
+
+# NodeJS
+node_modules/
+
+# Binaries
+bin/
+.out/
+out/
+dist/
+
+# Editors
+.vscode/

.gitmodules

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+[submodule "deps/petsc"]
+	path = deps/petsc
+	url = https://gitlab.com/petsc/petsc.git
+	branch = release

Makefile

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+PETSC_DIR = ./deps/petsc
+PETSC_ARCH = arch-linux-c-debug
+
+petsc.pc := $(PETSC_DIR)/$(PETSC_ARCH)/lib/pkgconfig/petsc.pc
+
+PACKAGES := $(petsc.pc)
+
+CC := $(shell pkg-config --variable=ccompiler $(PACKAGES))
+CXX := $(shell pkg-config --variable=cxxcompiler $(PACKAGES))
+FC := $(shell pkg-config --variable=fcompiler $(PACKAGES))
+CFLAGS_OTHER := $(shell pkg-config --cflags-only-other $(PACKAGES))
+CFLAGS := $(shell pkg-config --variable=cflags_extra $(PACKAGES)) $(CFLAGS_OTHER)
+CXXFLAGS := $(shell pkg-config --variable=cxxflags_extra $(PACKAGES)) $(CFLAGS_OTHER)
+FFLAGS := $(shell pkg-config --variable=fflags_extra $(PACKAGES))
+CPPFLAGS := $(shell pkg-config --cflags-only-I $(PACKAGES))
+LDFLAGS := $(shell pkg-config --libs-only-L --libs-only-other $(PACKAGES))
+LDFLAGS += $(patsubst -L%, $(shell pkg-config --variable=ldflag_rpath $(PACKAGES))%, $(shell pkg-config --libs-only-L $(PACKAGES)))
+LDLIBS := $(shell pkg-config --libs-only-l $(PACKAGES)) -lm
+CUDAC := $(shell pkg-config --variable=cudacompiler $(PACKAGES))
+CUDAC_FLAGS := $(shell pkg-config --variable=cudaflags_extra $(PACKAGES))
+CUDA_LIB := $(shell pkg-config --variable=cudalib $(PACKAGES))
+CUDA_INCLUDE := $(shell pkg-config --variable=cudainclude $(PACKAGES))
+
+all: setup main
+
+setup:
+	mkdir -p bin
+	mkdir -p deps
+
+print:
+	@echo ====== PETSc ======
+	@echo PETSC_DIR=$(PETSC_DIR)
+	@echo PETSC_ARCH=$(PETSC_ARCH)
+	@echo ====== Compilers ======
+	@echo CC=$(CC)
+	@echo CXX=$(CXX)
+	@echo FC=$(FC)
+	@echo COMPILE.cc=$(COMPILE.cc)
+	@echo LINK.cc=$(LINK.cc)
+	@echo ====== Flags ======
+	@echo CFLAGS=$(CFLAGS)
+	@echo CXXFLAGS=$(CXXFLAGS)
+	@echo FFLAGS=$(FFLAGS)
+	@echo CPPFLAGS=$(CPPFLAGS)
+	@echo LDFLAGS=$(LDFLAGS)
+	@echo LDLIBS=$(LDLIBS)
+	@echo ====== Cuda ======
+	@echo CUDAC=$(CUDAC)
+	@echo CUDAC_FLAGS=$(CUDAC_FLAGS)
+	@echo CUDA_LIB=$(CUDA_LIB)
+	@echo CUDA_INCLUDE=$(CUDA_INCLUDE)
+
+bin/% : %.c
+	$(LINK.cc) -o $@ $^ $(LDLIBS)
+bin/%.o: %.cxx
+	$(COMPILE.cc) $(OUTPUT_OPTION) $<
+bin/%.o: %.c
+	$(CC) $(OUTPUT_OPTION) $<
+bin/%.o : %.cu
+	$(CUDAC) -c $(CPPFLAGS) $(CUDAC_FLAGS) $(CUDA_INCLUDE) -o $@ $<

README.md

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+# Progetto di Calcolo Scientifico
+
+Metodo di Arnoldi per autovalori utilizzando PETSc.
+
+## Setup
+
+```bash
+$ git submodule init
+$ git submodule update
+
+$ cd deps/petsc
+$ ./configure
+$ make
+```
+
+## Compile
+
+```bash
+$ make all
+```

deps/petsc

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+Subproject commit 6903f0243818938898d808bb21b0de29ccfe6a88

main.c

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+static char help[] = "Solves a tridiagonal linear system with KSP.\n\n";
+
+#include <petscksp.h>
+#include <petscerror.h>
+
+int main(int argc, char **args)
+{
+  Vec         x, b, u; /* approx solution, RHS, exact solution */
+  Mat         A;       /* linear system matrix */
+  KSP         ksp;     /* linear solver context */
+  PC          pc;      /* preconditioner context */
+  PetscReal   norm;    /* norm of solution error */
+  PetscInt    i, n = 10, col[3], its;
+  PetscMPIInt size;
+  PetscScalar value[3];
+
+  PetscFunctionBeginUser;
+  PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
+  PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
+  PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This is a uniprocessor example only!");
+
+  PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
+
+  PetscCall(VecCreate(PETSC_COMM_SELF, &x));
+  PetscCall(PetscObjectSetName((PetscObject)x, "Solution"));
+  PetscCall(VecSetSizes(x, PETSC_DECIDE, n));
+  PetscCall(VecSetFromOptions(x));
+  PetscCall(VecDuplicate(x, &b));
+  PetscCall(VecDuplicate(x, &u));
+
+  PetscCall(MatCreate(PETSC_COMM_SELF, &A));
+  PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, n, n));
+  PetscCall(MatSetFromOptions(A));
+  PetscCall(MatSetUp(A));
+
+  value[0] = -1.0;
+  value[1] = 2.0;
+  value[2] = -1.0;
+  for (i = 1; i < n - 1; i++) {
+    col[0] = i - 1;
+    col[1] = i;
+    col[2] = i + 1;
+    PetscCall(MatSetValues(A, 1, &i, 3, col, value, INSERT_VALUES));
+  }
+  i      = n - 1;
+  col[0] = n - 2;
+  col[1] = n - 1;
+  PetscCall(MatSetValues(A, 1, &i, 2, col, value, INSERT_VALUES));
+  i        = 0;
+  col[0]   = 0;
+  col[1]   = 1;
+  value[0] = 2.0;
+  value[1] = -1.0;
+  PetscCall(MatSetValues(A, 1, &i, 2, col, value, INSERT_VALUES));
+  PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
+  PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
+
+  PetscCall(VecSet(u, 1.0));
+  PetscCall(MatMult(A, u, b));
+
+  PetscCall(KSPCreate(PETSC_COMM_SELF, &ksp));
+
+  PetscCall(KSPSetOperators(ksp, A, A));
+
+  PetscCall(KSPGetPC(ksp, &pc));
+  PetscCall(PCSetType(pc, PCJACOBI));
+  PetscCall(KSPSetTolerances(ksp, 1.e-5, PETSC_DEFAULT, PETSC_DEFAULT, PETSC_DEFAULT));
+
+  PetscCall(KSPSetFromOptions(ksp));
+
+  PetscCall(KSPSolve(ksp, b, x));
+
+  PetscCall(VecAXPY(x, -1.0, u));
+  PetscCall(VecNorm(x, NORM_2, &norm));
+  PetscCall(KSPGetIterationNumber(ksp, &its));
+  PetscCall(PetscPrintf(PETSC_COMM_SELF, "Norm of error %g, Iterations %" PetscInt_FMT "\n", (double)norm, its));
+
+  PetscCall(MatShift(A, 2.0));
+  PetscCall(KSPSolve(ksp, b, x));
+
+  PetscCall(KSPDestroy(&ksp));
+
+  if (PCMPIServerActive) {
+    PetscCall(KSPCreate(PETSC_COMM_SELF, &ksp));
+    PetscCall(KSPSetOptionsPrefix(ksp, "prefix_test_"));
+    PetscCall(MatSetOptionsPrefix(A, "prefix_test_"));
+    PetscCall(KSPSetOperators(ksp, A, A));
+    PetscCall(KSPSetFromOptions(ksp));
+    PetscCall(KSPSolve(ksp, b, x));
+    PetscCall(KSPDestroy(&ksp));
+  }
+
+  PetscCall(VecDestroy(&x));
+  PetscCall(VecDestroy(&u));
+  PetscCall(VecDestroy(&b));
+  PetscCall(MatDestroy(&A));
+
+  PetscCall(PetscFinalize());
+  return 0;
+}