Extract function into random_polynomial_matrix.h

This code is test-only, and uses uncontrolled randomness, so doesn't belong in the common library. (It also happens to break with Eigen 3.2, so got in my way.)
zieperz · Oct 13, 2016 · 01eec0b · 01eec0b
1 parent c1d81ae
commit 01eec0b
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Showing 5 changed files with 42 additions and 24 deletions.
diff --git a/drake/common/polynomial.h b/drake/common/polynomial.h
@@ -423,22 +423,6 @@ class DRAKE_EXPORT Polynomial {
     return os;
   }
 
-  /// Obtains a matrix of random unvariate Polynomials of the specified size.
-  static Eigen::Matrix<Polynomial, Eigen::Dynamic, Eigen::Dynamic>
-  RandomPolynomialMatrix(Eigen::Index num_coefficients_per_polynomial,
-                         Eigen::Index rows, Eigen::Index cols) {
-    Eigen::Matrix<Polynomial, Eigen::Dynamic, Eigen::Dynamic> mat(rows, cols);
-    for (Eigen::Index row = 0; row < mat.rows(); ++row) {
-      for (Eigen::Index col = 0; col < mat.cols(); ++col) {
-        auto coeffs =
-            (Eigen::Matrix<CoefficientType, Eigen::Dynamic, 1>::Random(
-                 num_coefficients_per_polynomial)).eval();
-        mat(row, col) = Polynomial(coeffs);
-      }
-    }
-    return mat;
-  }
-
   //@{
   /** Variable name/ID conversion facility. */
   static bool IsValidVariableName(const std::string name);

diff --git a/drake/common/test/polynomial_test.cc b/drake/common/test/polynomial_test.cc
@@ -8,6 +8,7 @@
 #include "gtest/gtest.h"
 
 #include "drake/common/eigen_matrix_compare.h"
+#include "drake/common/test/random_polynomial_matrix.h"
 
 using Eigen::VectorXd;
 using std::default_random_engine;
@@ -146,12 +147,12 @@ void testPolynomialMatrix() {
   int rows_B = cols_A;
   int cols_B = matrix_size_distribution(generator);
 
-  auto A = Polynomial<CoefficientType>::RandomPolynomialMatrix(num_coefficients,
-                                                               rows_A, cols_A);
-  auto B = Polynomial<CoefficientType>::RandomPolynomialMatrix(num_coefficients,
-                                                               rows_B, cols_B);
-  auto C = Polynomial<CoefficientType>::RandomPolynomialMatrix(num_coefficients,
-                                                               rows_A, cols_A);
+  auto A = test::RandomPolynomialMatrix<CoefficientType>(num_coefficients,
+                                                         rows_A, cols_A);
+  auto B = test::RandomPolynomialMatrix<CoefficientType>(num_coefficients,
+                                                         rows_B, cols_B);
+  auto C = test::RandomPolynomialMatrix<CoefficientType>(num_coefficients,
+                                                         rows_A, cols_A);
   auto product = A * B;
   auto sum = A + C;
 

diff --git a/drake/common/test/random_polynomial_matrix.h b/drake/common/test/random_polynomial_matrix.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include "drake/common/polynomial.h"
+
+namespace drake {
+namespace test {
+
+/// Obtains a matrix of random unvariate Polynomials of the specified size.
+template <typename CoefficientType = double>
+static Eigen::Matrix<Polynomial<CoefficientType>,
+                     Eigen::Dynamic, Eigen::Dynamic>
+RandomPolynomialMatrix(Eigen::Index num_coefficients_per_polynomial,
+                       Eigen::Index rows, Eigen::Index cols) {
+  Eigen::Matrix<Polynomial<CoefficientType>, Eigen::Dynamic, Eigen::Dynamic>
+      mat(rows, cols);
+  for (Eigen::Index row = 0; row < mat.rows(); ++row) {
+    for (Eigen::Index col = 0; col < mat.cols(); ++col) {
+      auto coeffs =
+          (Eigen::Matrix<CoefficientType, Eigen::Dynamic, 1>::Random(
+              num_coefficients_per_polynomial)).eval();
+      mat(row, col) = Polynomial<CoefficientType>(coeffs);
+    }
+  }
+  return mat;
+}
+
+}  // namespace test
+}  // namespace drake
diff --git a/drake/systems/trajectories/PiecewisePolynomial.cpp b/drake/systems/trajectories/PiecewisePolynomial.cpp
@@ -1,6 +1,7 @@
 #include "drake/systems/trajectories/PiecewisePolynomial.h"
 
 #include "drake/common/drake_assert.h"
+#include "drake/common/test/random_polynomial_matrix.h"
 
 using namespace std;
 using namespace Eigen;
@@ -320,6 +321,9 @@ Eigen::Index PiecewisePolynomial<CoefficientType>::cols() const {
         "PiecewisePolynomial has no segments. Number of columns is undefined.");
 }
 
+// TODO(jwnimmer-tri) This method should move into legacy test-only code (in
+// other words, some other class and header).  Unseeded randomness leads to
+// hard-to-debug failures.
 template <typename CoefficientType>
 PiecewisePolynomial<CoefficientType> PiecewisePolynomial<
   CoefficientType>::random(Eigen::Index rows, Eigen::Index cols,
@@ -331,7 +335,7 @@ PiecewisePolynomial<CoefficientType> PiecewisePolynomial<
   for (Eigen::Index segment_index = 0; segment_index < num_segments;
        ++segment_index) {
     polynomials.push_back(
-        PolynomialType::RandomPolynomialMatrix(
+        drake::test::RandomPolynomialMatrix<CoefficientType>(
             num_coefficients_per_polynomial, rows, cols));
   }
   return PiecewisePolynomial<CoefficientType>(polynomials, segment_times);

diff --git a/drake/util/test/testLCMUtil.cpp b/drake/util/test/testLCMUtil.cpp
@@ -1,4 +1,5 @@
 #include "drake/common/eigen_matrix_compare.h"
+#include "drake/common/test/random_polynomial_matrix.h"
 #include "drake/math/random_rotation.h"
 #include "drake/util/lcmUtil.h"
 
@@ -25,7 +26,7 @@ GTEST_TEST(TestLcmUtil, testPolynomial) {
 }
 
 GTEST_TEST(TestLcmUtil, testPolynomialMatrix) {
-  auto poly_matrix = Polynomial<double>::RandomPolynomialMatrix(6, 5, 8);
+  auto poly_matrix = drake::test::RandomPolynomialMatrix<double>(6, 5, 8);
   drake::lcmt_polynomial_matrix msg;
   encodePolynomialMatrix<Eigen::Dynamic, Eigen::Dynamic>(poly_matrix, msg);
   EXPECT_EQ(static_cast<int>(msg.rows), static_cast<int>(poly_matrix.rows()));