New set-up for homework code for Chapter Introduction

Assignments/Codes/Introduction/MatrixClass/CodeExpert/export.json

+{
+  "cxweb": "4.0.5",
+  "cxrun": "2.0.1"
+}

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/MatrixClass.hpp

+#ifndef MATRIXCLASS_HPP
+#define MATRIXCLASS_HPP
+
+// The purpose of this exercise is to introduce the Eigen::Matrix class.
+
+#include <iostream>
+
+// TO DO: Include the "Eigen/Dense" header file with #include <Eigen/Dense>
+// START
+#include <Eigen/Dense>
+// END
+
+/* SAM_LISTING_BEGIN_0 */
+Eigen::Matrix2d smallTriangular( double a, double b, double c ){
+  /* 
+   * This functions returns a 2 by 2 triangular matrix of doubles a, b, c.
+   */
+  
+  // We know in advance that we want to create a matrix of doubles with a fixed size of 2 by 2.
+  // Therefore, we pass the parameters <double, 2, 2> to the template class Eigen::Matrix.
+  Eigen::Matrix< double, 2, 2 > A;
+  
+  // We have declared the variable A of the type Eigen::Matrix<double,2,2>,
+  // but we have not initialized its entries.
+  // We can do this using comma-initialization:
+  A << a, b, 0, c;
+  
+  // Question: Is A now an upper triangular matrix, or a lower triangular matrix?
+  
+  return A;
+}
+/* SAM_LISTING_END_0 */
+
+Eigen::MatrixXd constantTriangular( int n, double val ){
+    /*
+     * This function returns an n by n upper triangular matrix with the constant value val in the upper triangular part.
+     */
+    
+    // Now we do not know the size of our matrix at compile time.
+    // Hence, we use the special value Eigen::Dynamic to set the size of A.
+    Eigen::Matrix< double, Eigen::Dynamic, Eigen::Dynamic > A;
+    
+    // Eigen::Matrix has a method Zero(n_rows,n_cols) which returns the n_rows by n_cols matrix whose entries are all equal to zero.
+    A = Eigen::Matrix< double, Eigen::Dynamic, Eigen::Dynamic >::Zero( n, n );
+    
+    // To get a triangular matrix, we must set the values above the diagonal to val.
+    // This we can do by a nested for-loop.
+    for(int row = 0; row < n; row++){
+        
+        // TO DO: Write the inner for-loop.
+        // Hint: We can access and change the entries of A using parentheses, i.e. A(row,col) = val;
+        // Note that indexing starts at the value 0 (as usual), and not 1 (as in Matlab).
+        
+        // START
+        for(int col=row; col<n; col++){
+            A( row, col ) = val;
+            }
+        // END
+        }
+    
+    //std::cout << A << std::endl;
+    
+    return A;
+    }
+
+Eigen::VectorXd arithmetics(int m, int n){
+    /*
+     * This function does not do anything meaningful.
+     * It is only meant to show some simple Eigen arithmetics and matrix initializations.
+     */
+    
+    // Because the syntax Eigen::Matrix< type, n_rows, n_cols > is very cumbersome,
+    // Eigen provides convenience classes that work as shorthands.
+    // For example, Eigen::Matrix2d is shorthand for Eigen::Matrix< double, 2, 2 >.
+    
+    // This declares dynamic size (signified by the letter 'X') matrices of doubles (signified by the letter 'd').
+    Eigen::MatrixXd A, B, C, I;
+    
+    // We initialize the matrices arbitrarily.
+    A = constantTriangular( n, 5.0 ).transpose(); // an n by n lower triangular matrix
+    B = Eigen::MatrixXd::Random( m, n ); // a random m by n matrix with values between -1 and 1.
+    I = Eigen::MatrixXd::Identity( n, n ); // The n by n identity matrix.
+    
+    // We can perform arithmetics on matrices: +, -, *
+    // Note that for + and -, the left hand matrix and the right hand matrix have to be the same size,
+    // and that matrix multiplication * is only defined if the number of columns
+    // in the left hand matrix is the same as the number of rows in the right hand matrix.
+    C = B*(A - 5.0*I);
+    
+    // Eigen::VectorXd is shorthand for Eigen::Matrix< double, Eigen::Dynamic, 1 >.
+    // Hence, all the same arithmetics work for vectors.
+    Eigen::VectorXd u, v;
+    
+    // TO DO: Initialize the entries of u as the integers from 1 to n, multiply u by the matrix C, and store the result in v.
+    // START
+    u = Eigen::VectorXd::LinSpaced( n, 1, n ); // Or use a for-loop.
+    v = C*u;
+    // END
+    
+    //std::cout<<v<<std::endl;
+    
+    return v;
+    }
+
+
+double casting(){
+    /*
+     * This function does not do anything meaningful.
+     * It is only meant to introduce a few more typedefs and how to cast them. 
+     */
+    
+    // RowVectorXi is a shorthand for Eigen::Matrix< int, 1, Eigen::Dynamic >
+    // Constant(2,1) creates a vector of size 2 and initializes the entries with the value 1.
+    Eigen::RowVectorXi u = Eigen::RowVectorXi::Constant(2,1);
+    
+    // std::complex is a template class for complex numbers.
+    // Here we declare two complex numbers, with real and imaginary parts represented by doubles.
+    // z0 = 1 - i
+    // z1 = 5 + i
+    std::complex<double> z0(1,-1), z1(5,1);
+    
+    // Declare and initialize a size 2 vector of std::complex<double>.
+    Eigen::Vector2cd v;
+    v(0) = z0;
+    v(1) = z1;
+    
+    double x;
+    // TO DO: Calculate u*v and store the result in x.
+    // Hint: First use u.cast< NEW TYPE >() to cast the "int" vector u to a "std::complex<double>" vector.
+    // The result will be u*v = 1*(1-i) + 1*(5+i) = 6 + 0i, a real number. You can get the real part of a std::complex<double> by .real().
+    // START
+    std::complex<double> z = u.cast<std::complex<double>>()*v;
+    x = z.real();
+    // END
+    
+    return x;
+    }
+
+
+#endif

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/conf.yml

+# Code Expert Generic Project Configuration.
+#
+# In case this file is omitted, the execution is done with the default values.
+
+# You can either define a cmd or a script file to be executed.
+# Default to script file setting a cmd overrides it.
+cmd:
+#  compile: echo "COMPILE"
+#  run: echo "RUN"
+#  test: echo "TEST"
+#  submit: echo "SUBMIT"
+
+# All scripts are set by default to "/scripts/${ACTION}.sh"
+script:
+  compile: /scripts/compile.sh
+  run: /scripts/run.sh
+  test: /scripts/test.sh
+  submit: /scripts/submit.sh
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/cx_description/conf.yml

+descriptions:
+  default:
+    name: Default
+    default: true
+# Optionally add mulitple versions here.
+# Use the file name without the .md extension as key and add a `name:` to it.
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/cx_description/default.md

+
+# Tutorial: part 1/3
+## The Eigen::Matrix template class
+
+> The purpose of this exercise is to learn to declare and initialize [Eigen::Matrix objects](https://eigen.tuxfamily.org/dox/group__TutorialMatrixClass.html), and to get familiar with some handy typedefs and methods.
+
+> Open "MatrixClass.hpp" and fill in the missing code in between the delimiters `// START` and `// END` according to the instructions preceded by `// TO DO:`.
+
+> Read each function of the program carefully. The code will not compile until after the first task is finished, which is to include Eigen/Dense.
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/cx_description/test_doc.md

+
+
+# Tests of MatrixClass.hpp
+
+> There are four functions in MatrixClass.hpp and main.cpp has one test for each function.
+***
+> `smallTriangular(double a, double b, double c)`: This function does not need to be edited, so the first test is passed automatically as long as the code compiles. The function takes as arguments three doubles and creates a 2 by 2 upper triangular matrix from those numbers.
+The test prints `smallTriangular(1,2,3)`, and the correct result is:
+```
+  1 2
+  0 3
+```
+***
+> `constantTriangular(int n, double val)`: This function creates an n by n triangular MatrixXd with the entries in upper triangular part equal to `val`.
+The test prints `constantTriangular(3,20)`, and the correct result is:
+```
+  20 20 20
+   0 20 20
+   0  0 20
+```
+***
+> `arithmetics(int m, int n)`: This function performs some arbitrary arithmetics on a random m by n matrix (the random seed is fixed).
+The test prints `arithmetics(2,5)`, and the correct result is:
+```
+  -18.983
+  19.4972
+```
+***
+> `casting()`: This function calculates the inner product of the integer vector `[2 1]` and the complex vector `[1-i, 5+i]` and returns the real part as a double.
+The test prints `casting()`, and the correct result is:
+```
+  6
+```

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/main.cpp

+
+#include "MatrixClass.hpp"
+
+int main(){
+    
+    std::cout<< "\nTest of smallTriangular():\n";
+    std::cout<< smallTriangular(1,2,3) << std::endl;
+    std::cout<< "\nTest of constantTriangular():\n";
+    std::cout<< constantTriangular(3,20) << std::endl;
+    std::cout<< "\nTest of arithmetics():\n";
+    std::srand(5); // So that random behaviour is predictable.
+    std::cout<< arithmetics(2,5) << std::endl;
+    std::cout<< "\nTest of casting():\n";
+    std::cout<< casting() << std::endl;    
+
+    return 0;
+    }

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/scripts/compile.sh

+#!/bin/bash
+
+echo "Compiling ..."
+
+
+# compile c code
+# find . -iname '*.cpp' | sort | xargs g++ -fdiagnostics-color=always --pedantic -Wextra -Wall -std=c++14  -I/usr/include/python3.7m -llibpython  -o bin/a.out || exit 1
+
+# Compiling for 'matplotlibcpp.h'
+mkdir -p bin
+
+find . -iname '*.cpp' | sort | xargs \
+  g++ -fdiagnostics-color=always -std=c++11 \
+  -I/usr/local/include/python3.7m \
+  -I/usr/local/lib/python3.7/site-packages/numpy/core/include \
+  -I/usr/include/eigen3/ \
+  -lpython3.7m \
+  -lpthread -lutil -ldl \
+  -Xlinker -export-dynamic \
+  -o bin/a.out
+
+
+echo "Compilation successful"
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/scripts/run.sh

+#!/bin/bash
+
+export PYTHONIOENCODING="UTF-8"
+
+# compile (call compile script)
+bash "${WORKDIR}/scripts/compile.sh"
+
+# run
+bin/a.out 
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/scripts/submit.sh

+#!/bin/bash
+
+echo "Not implemented"
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/scripts/test.sh

+#!/bin/bash
+
+# run (call run script)
+bash "${WORKDIR}/scripts/run.sh"
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/solution/tests.csv

+// "testname", "input", "expected output", "points", "execution time limit (ms)"
+"smallTriangular", "(any input)", "1 2\n0 3",  "1", "5000",
+"constantTriangular", "(any input)", "20 20 20\n 0 20 20\n 0  0 20",  "1", "5000",
+"arithmetics", "(any input)", "-18.983\n19.4972",  "1", "5000",
+"casting", "(any input)", "6",  "1", "5000",
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/MatrixClass.hpp

+#ifndef MATRIXCLASS_HPP
+#define MATRIXCLASS_HPP
+
+// The purpose of this exercise is to introduce the Eigen::Matrix class.
+
+#include <iostream>
+
+// TO DO: Include the "Eigen/Dense" header file with #include <Eigen/Dense>
+// START
+
+// END
+
+Eigen::Matrix2d smallTriangular( double a, double b, double c ){
+    /* 
+     * This functions returns a 2 by 2 triangular matrix of doubles a, b, c.
+     */
+    
+    // We know in advance that we want to create a matrix of doubles with a fixed size of 2 by 2.
+    // Therefore, we pass the parameters <double, 2, 2> to the template class Eigen::Matrix.
+    Eigen::Matrix< double, 2, 2 > A;
+    
+    // We have declared the variable A of the type Eigen::Matrix<double,2,2>,
+    // but we have not initialized its entries.
+    // We can do this using comma-initialization:
+    A << a, b, 0, c;
+    
+    // Question: Is A now an upper triangular matrix, or a lower triangular matrix?
+    
+    return A;
+    }
+
+Eigen::MatrixXd constantTriangular( int n, double val ){
+    /*
+     * This function returns an n by n upper triangular matrix with the constant value val in the upper triangular part.
+     */
+    
+    // Now we do not know the size of our matrix at compile time.
+    // Hence, we use the special value Eigen::Dynamic to set the size of A.
+    Eigen::Matrix< double, Eigen::Dynamic, Eigen::Dynamic > A;
+    
+    // Eigen::Matrix has a method Zero(n_rows,n_cols) which returns the n_rows by n_cols matrix whose entries are all equal to zero.
+    A = Eigen::Matrix< double, Eigen::Dynamic, Eigen::Dynamic >::Zero( n, n );
+    
+    // To get a triangular matrix, we must set the values above the diagonal to val.
+    // This we can do by a nested for-loop.
+    for(int row = 0; row < n; row++){
+        
+        // TO DO: Write the inner for-loop.
+        // Hint: We can access and change the entries of A using parentheses, i.e. A(row,col) = val;
+        // Note that indexing starts at the value 0 (as usual), and not 1 (as in Matlab).
+        
+        // START
+        
+        // END
+        }
+    
+    return A;
+    }
+
+Eigen::VectorXd arithmetics(int m, int n){
+    /*
+     * This function does not do anything meaningful.
+     * It is only meant to show some simple Eigen arithmetics and matrix initializations.
+     */
+    
+    // Because the syntax Eigen::Matrix< type, n_rows, n_cols > is very cumbersome,
+    // Eigen provides convenience classes that work as shorthands.
+    // For example, Eigen::Matrix2d is shorthand for Eigen::Matrix< double, 2, 2 >.
+    
+    // This declares dynamic size (signified by the letter 'X') matrices of doubles (signified by the letter 'd').
+    Eigen::MatrixXd A, B, C, I;
+    
+    // We initialize the matrices arbitrarily.
+    A = constantTriangular( n, 5.0 ).transpose(); // an n by n lower triangular matrix
+    B = Eigen::MatrixXd::Random( m, n ); // a random m by n matrix with values between -1 and 1.
+    I = Eigen::MatrixXd::Identity( n, n ); // The n by n identity matrix.
+    
+    // We can perform arithmetics on matrices: +, -, *
+    // Note that for + and -, the left hand matrix and the right hand matrix have to be the same size,
+    // and that matrix multiplication * is only defined if the number of columns
+    // in the left hand matrix is the same as the number of rows in the right hand matrix.
+    C = B*(A - 5.0*I);
+    
+    // Eigen::VectorXd is shorthand for Eigen::Matrix< double, Eigen::Dynamic, 1 >.
+    // Hence, all the same arithmetics work for vectors.
+    Eigen::VectorXd u, v;
+    
+    // TO DO: Initialize the entries of u as the integers from 1 to n, multiply u by the matrix C, and store the result in v.
+    // START
+    
+    // END
+    
+    
+    return v;
+    }
+
+
+double casting(){
+    /*
+     * This function does not do anything meaningful.
+     * It is only meant to introduce a few more typedefs and how to cast them. 
+     */
+    
+    // RowVectorXi is a shorthand for Eigen::Matrix< int, 1, Eigen::Dynamic >
+    // Constant(2,1) creates a vector of size 2 and initializes the entries with the value 1.
+    Eigen::RowVectorXi u = Eigen::RowVectorXi::Constant(2,1);
+    
+    // std::complex is a template class for complex numbers.
+    // Here we declare two complex numbers, with real and imaginary parts represented by doubles.
+    // z0 = 1 - i
+    // z1 = 5 + i
+    std::complex<double> z0(1,-1), z1(5,1);
+    
+    // Declare and initialize a size 2 vector of std::complex<double>.
+    Eigen::Vector2cd v;
+    v(0) = z0;
+    v(1) = z1;
+    
+    double x;
+    // TO DO: Calculate u*v and store the result in x.
+    // Hint: First use u.cast< NEW TYPE >() to cast the "int" vector u to a "std::complex<double>" vector.
+    // The result will be u*v = 1*(1-i) + 1*(5+i) = 6 + 0i, a real number. You can get the real part of a std::complex<double> by .real().
+    // START
+    
+    // END
+    
+    return x;
+    }
+
+
+#endif

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/conf.yml

+# Code Expert Generic Project Configuration.
+#
+# In case this file is omitted, the execution is done with the default values.
+
+# You can either define a cmd or a script file to be executed.
+# Default to script file setting a cmd overrides it.
+cmd:
+#  compile: echo "COMPILE"
+#  run: echo "RUN"
+#  test: echo "TEST"
+#  submit: echo "SUBMIT"
+
+# All scripts are set by default to "/scripts/${ACTION}.sh"
+script:
+  compile: /scripts/compile.sh
+  run: /scripts/run.sh
+  test: /scripts/test.sh
+  submit: /scripts/submit.sh
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/cx_description/conf.yml

+descriptions:
+  default:
+    name: Default
+    default: true
+# Optionally add mulitple versions here.
+# Use the file name without the .md extension as key and add a `name:` to it.
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/cx_description/default.md

+
+# Tutorial: part 1/3
+## The Eigen::Matrix template class
+
+> The purpose of this exercise is to learn to declare and initialize [Eigen::Matrix objects](https://eigen.tuxfamily.org/dox/group__TutorialMatrixClass.html), and to get familiar with some handy typedefs and methods.
+
+> Open "MatrixClass.hpp" and fill in the missing code in between the delimiters `// START` and `// END` according to the instructions preceded by `// TO DO:`.
+
+> Read each function of the program carefully. The code will not compile until after the first task is finished, which is to include Eigen/Dense.
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/cx_description/test_doc.md

+
+
+# Tests of MatrixClass.hpp
+
+> There are four functions in MatrixClass.hpp and main.cpp has one test for each function.
+***
+> `smallTriangular(double a, double b, double c)`: This function does not need to be edited, so the first test is passed automatically as long as the code compiles. The function takes as arguments three doubles and creates a 2 by 2 upper triangular matrix from those numbers.
+The test prints `smallTriangular(1,2,3)`, and the correct result is:
+```
+  1 2
+  0 3
+```
+***
+> `constantTriangular(int n, double val)`: This function creates an n by n triangular MatrixXd with the entries in upper triangular part equal to `val`.
+The test prints `constantTriangular(3,20)`, and the correct result is:
+```
+  20 20 20
+   0 20 20
+   0  0 20
+```
+***
+> `arithmetics(int m, int n)`: This function performs some arbitrary arithmetics on a random m by n matrix (the random seed is fixed).
+The test prints `arithmetics(2,5)`, and the correct result is:
+```
+  -18.983
+  19.4972
+```
+***
+> `casting()`: This function calculates the inner product of the integer vector `[2 1]` and the complex vector `[1-i, 5+i]` and returns the real part as a double.
+The test prints `casting()`, and the correct result is:
+```
+  6
+```

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/main.cpp

+
+#include "MatrixClass.hpp"
+
+int main(){
+    
+    std::cout<< "\nTest of smallTriangular():\n";
+    std::cout<< smallTriangular(1,2,3) << std::endl;
+    std::cout<< "\nTest of constantTriangular():\n";
+    std::cout<< constantTriangular(3,20) << std::endl;
+    std::cout<< "\nTest of arithmetics():\n";
+    std::srand(5); // So that random behaviour is predictable.
+    std::cout<< arithmetics(2,5) << std::endl;
+    std::cout<< "\nTest of casting():\n";
+    std::cout<< casting() << std::endl;    
+
+    return 0;
+    }

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/scripts/compile.sh

+#!/bin/bash
+
+echo "Compiling ..."
+
+
+# compile c code
+# find . -iname '*.cpp' | sort | xargs g++ -fdiagnostics-color=always --pedantic -Wextra -Wall -std=c++14  -I/usr/include/python3.7m -llibpython  -o bin/a.out || exit 1
+
+# Compiling for 'matplotlibcpp.h'
+mkdir -p bin
+
+find . -iname '*.cpp' | sort | xargs \
+  g++ -fdiagnostics-color=always -std=c++11 \
+  -I/usr/local/include/python3.7m \
+  -I/usr/local/lib/python3.7/site-packages/numpy/core/include \
+  -I/usr/include/eigen3/ \
+  -lpython3.7m \
+  -lpthread -lutil -ldl \
+  -Xlinker -export-dynamic \
+  -o bin/a.out
+
+
+echo "Compilation successful"
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/scripts/run.sh

+#!/bin/bash
+
+export PYTHONIOENCODING="UTF-8"
+
+# compile (call compile script)
+bash "${WORKDIR}/scripts/compile.sh"
+
+# run
+bin/a.out 
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/scripts/submit.sh

+#!/bin/bash
+
+echo "Not implemented"
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/scripts/test.sh

+#!/bin/bash
+
+# run (call run script)
+bash "${WORKDIR}/scripts/run.sh"
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/CodeExpert/template/tests.csv

+// "testname", "input", "expected output", "points", "execution time limit (ms)"
+"smallTriangular", "(any input)", "1 2\n0 3",  "1", "5000",
+"constantTriangular", "(any input)", "20 20 20\n 0 20 20\n 0  0 20",  "1", "5000",
+"arithmetics", "(any input)", "-18.983\n19.4972",  "1", "5000",
+"casting", "(any input)", "6",  "1", "5000",
\ No newline at end of file

Assignments/Codes/Introduction/MatrixClass/MatrixClass.hpp

+CodeExpert/solution/MatrixClass.hpp
\ No newline at end of file