Use Matrix initializer_list constructor instead of comma initializers

[Gold856]

As promised :) One thing I wasn't exactly sure what to do was if I should use fixed size matrix types, or continue using the dynamically sized matrix types. I mostly opted for the dynamically sized matrix types, but I suspect fixed size would be better for ensuring correct initialization of matrices.

Also, happy 4th of July! 🎆

[dellaert]

Awesome. But dynamic vs static should be changed deliberately. For Jacobians in particular, we don't want to incur extra overhead. That depends on the way the Jacobian arguments are given; some already are static and so we should not have a dynamic malloc there.

[Copilot]

Pull request overview

This PR modernizes GTSAM’s examples, timing benchmarks, library code, and tests by replacing Eigen comma-initializers (<< ... .finished()) with brace/initializer_list-style construction for Matrix/Vector types.

Changes:

• Replaced Eigen comma-initializers with brace/initializer-list constructors across timing code, examples, and tests.
• Updated various fixed-size Eigen types (Vector6, Matrix3, etc.) to use direct brace initialization.
• Cleaned up a few small formatting/include details alongside the initializer migration.

Reviewed changes

Copilot reviewed 201 out of 201 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
timing/timeRot3.cpp	Replace Vector comma-init with braces
timing/timePose3.cpp	Replace Vector/Expmap init with braces
timing/timePose2.cpp	Replace Matrix/Vector comma-init with braces
timing/timeMatrix.cpp	Replace Matrix comma-init with braces
timing/timeLago.cpp	Replace noise-model sigma Vector init
timing/timeISAM2Covariance.cpp	Replace prior sigma Vector init
timing/timeGaussianFactor.cpp	Replace Matrix comma-init with braces
timing/timeCholesky.cpp	Replace Matrix comma-init with braces
timing/timeBayesTreeCovariance.cpp	Replace prior sigma Vector init
timing/timeActiveSetSolverComparison.cpp	Replace 1D Matrix/Vector constructors + brace init
timing/exportBayesTreeCovarianceVisuals.cpp	Replace prior sigma Vector init
tests/testPreconditioner.cpp	Replace Matrix/Vector comma-init with braces
tests/testIterative.cpp	Replace expected Vector init with braces
tests/testGaussianISAM2.cpp	Replace sigma Vector init with braces
tests/testGaussianFactorGraphB.cpp	Replace Matrix/Vector comma-init with braces
tests/testExtendedKalmanFilter.cpp	Replace Vector(1) init with braces
tests/testExpressionFactor.cpp	Replace expected Jacobian matrix init
tests/testBoundingConstraint.cpp	Replace small Jacobians and Vector(1) init
tests/smallExample.h	Replace small Matrix init with braces
gtsam/slam/tests/testStereoFactor.cpp	Replace expected Jacobian matrices init
gtsam/slam/tests/testSmartProjectionFactor.cpp	Replace VectorValues init with braces
gtsam/slam/tests/testRegularImplicitSchurFactor.cpp	Replace RHS Vector init with braces
gtsam/slam/tests/testProjectionFactor.cpp	Replace expected Jacobian matrices init
gtsam/slam/tests/testPriorFactor.cpp	Replace Vector6 comma-init with braces
gtsam/slam/tests/testPoseRotationPrior.cpp	Replace Vector(1) noise/error init
gtsam/slam/tests/testOrientedPlane3Factor.cpp	Replace sigma Vector init; formatting tweak needed
gtsam/slam/tests/testKarcherMeanFactor.cpp	Replace Vector6 init with braces
gtsam/slam/tests/testInitializePose3.cpp	Replace Vector/Matrix init with braces
gtsam/slam/tests/testGeneralSFMFactor.cpp	Replace landmark vector init style
gtsam/slam/tests/testGeneralSFMFactor_Cal3Bundler.cpp	Replace delta Vector init (currently broken)
gtsam/slam/tests/testFrobeniusFactor.cpp	Replace fixed-size vector/matrix init
gtsam/slam/tests/testEssentialMatrixFactor.cpp	Replace retract delta Vector init
gtsam/slam/RotateFactor.h	Replace returned Vector(3) construction
gtsam/slam/lago.cpp	Replace Vector(1)/Vector(2) init with braces
gtsam/slam/InitializePose3.cpp	Replace Vector(9) init with braces
gtsam/slam/dataset.cpp	Replace noise sigma Vector init
gtsam/slam/BoundingConstraint.h	Replace Vector(1) construction with braces
gtsam/sfm/tests/testTranslationFactor.cpp	Replace expected Vector3 init with braces
gtsam/sfm/tests/testShonanFactor.cpp	Replace fixed-size vector init
gtsam/sfm/tests/testSelfCalibrationFactor.cpp	Replace Vector(2) expected init
gtsam/sfm/SelfCalibrationFactor.h	Replace returned Vector(2) construction
gtsam/sam/tests/testRangeFactor.cpp	Replace Vector(1) expected init
gtsam/nonlinear/WhiteNoiseFactor.h	Replace scalar Matrix/Vector init with braces
gtsam/nonlinear/utilities.h	Replace Vector6 noise sigma init
gtsam/nonlinear/tests/testUtilities.cpp	Replace stored Vector init + expected Matrix init
gtsam/nonlinear/tests/testExtendedPriorFactor.cpp	Replace mean/expected_error Vector init
gtsam/nonlinear/tests/testBatchFixedLagSmoother.cpp	Replace sigma Vector init
gtsam/nonlinear/tests/testAdaptAutoDiff.cpp	Replace Vector9 init with braces
gtsam/nonlinear/NoiseModelFactorN.h	Update doc example Matrix init
gtsam/nonlinear/ISAM2Params.h	Update doc example Vector init
gtsam/navigation/tests/testNavStateImuEKF.cpp	Replace Matrix3 covariance init
gtsam/navigation/tests/testNavState.cpp	Replace Vector9 init with braces
gtsam/navigation/tests/testLieGroupEKF.cpp	Replace Matrix/Vector init with braces
gtsam/navigation/tests/testLeggedEstimatorFactors.cpp	Replace Matrix init with braces
gtsam/navigation/tests/testLeggedEstimator.cpp	Replace Matrix init with braces
gtsam/navigation/tests/testInvariantEKF.cpp	Replace Matrix/Vector init with braces
gtsam/navigation/tests/testImuFactor.cpp	Replace prior sigma vector init
gtsam/navigation/tests/testGal3ImuEKF.cpp	Replace Matrix3 covariance init
gtsam/navigation/tests/testEquivariantFilter.cpp	Replace Vector2 init with braces
gtsam/navigation/tests/testConstantVelocityFactor.cpp	Replace Vector9 expected init
gtsam/navigation/tests/testBarometricFactor.cpp	Replace Vector(1) init with braces
gtsam/navigation/NavState.h	Replace internal Matrix32 construction
gtsam/navigation/CarrierPhaseFactor.cpp	Replace scalar Matrix(1,1) init
gtsam/navigation/BarometricFactor.cpp	Replace Vector(1)/Matrix(1,1) init
gtsam/linear/VectorValues.h	Update example Vector init
gtsam/linear/tests/testVectorValues.cpp	Replace Vector init throughout tests
gtsam/linear/tests/testSparseEigen.cpp	Replace small Matrix init with braces
gtsam/linear/tests/testScatter.cpp	Use Matrix3 fixed-size init + constants
gtsam/linear/tests/testRegularJacobianFactor.cpp	Replace RHS/noise/init vectors
gtsam/linear/tests/testPowerMethod.cpp	Replace initial Vector init
gtsam/linear/tests/testGaussianDensity.cpp	Replace Matrix init with braces
gtsam/linear/tests/testBatchJacobianFactor.cpp	Replace A/B/b matrix/vector init
gtsam/linear/tests/testAcceleratedPowerMethod.cpp	Replace initial Vector init
gtsam/geometry/tests/testStereoCamera.cpp	Replace Matrix3 init in Pose3
gtsam/geometry/tests/testSOn.cpp	Replace Vector6 init with braces
gtsam/geometry/tests/testSO4.cpp	Replace Vector6 init with braces
gtsam/geometry/tests/testSO3.cpp	Replace Matrix3/Matrix init with braces
gtsam/geometry/tests/testSimilarity3.cpp	Replace sigma Vector init
gtsam/geometry/tests/testSerializationGeometry.cpp	Replace Vector15 init
gtsam/geometry/tests/testRot2.cpp	Replace Vector1/Vector expected init
gtsam/geometry/tests/testPoint2.cpp	Replace Matrix(1,2) init
gtsam/geometry/tests/testExtendedPose3.cpp	Replace Matrix3/Vector12 init
gtsam/geometry/tests/testEssentialMatrix.cpp	Replace retract delta Vector init
gtsam/geometry/tests/testCal3DS2.cpp	Replace Vector(3) init
gtsam/geometry/SL4.cpp	Replace temp matrices/vectors with brace init; minor formatting
gtsam/geometry/Rot3Q.cpp	Replace Matrix3 comma-init with braces
gtsam/geometry/Pose3.cpp	Replace static Matrix63 init
gtsam/geometry/Event.h	Replace static Matrix14 init
gtsam/geometry/Cal3Unified.cpp	Replace Vector(1) print construction
gtsam/geometry/Cal3Bundler.cpp	Replace Vector(5) print construction
gtsam/constrained/tests/testQpsParser.cpp	Replace 1D Matrix/Vector init
gtsam/constrained/tests/testNonlinearEqualityConstraint.cpp	Replace expected vectors init
gtsam/constrained/tests/testLpProblem.cpp	Replace Values Vector + JacobianFactor init
gtsam/constrained/tests/testAugmentedLagrangianOptimizer.cpp	Replace lambdaEq Vector init
gtsam/constrained/QpsParser.cpp	Replace scalar Matrix/Vector init
gtsam/basis/tests/testFourier.cpp	Replace coefficient vectors init
gtsam/basis/tests/testChebyshev2.cpp	Replace Weights/Vector6 init
gtsam/base/tests/testVerticalBlockMatrix.cpp	Replace Matrix6 init
gtsam/base/tests/testVector.cpp	Remove comma-init test; should add initializer-list test
gtsam/base/tests/testSerializationBase.cpp	Replace matrix/vector init in serialization tests
gtsam/base/tests/testOptionalJacobian.cpp	Replace Matrix23 init
gtsam/base/tests/testCholesky.cpp	Replace matrices init with braces
gtsam/base/Matrix.h	Replace skewSymmetric Matrix3 init
gtsam_unstable/slam/TransformBtwRobotsUnaryFactorEM.h	Replace returned Vector(2) init
gtsam_unstable/slam/tests/testSmartRangeFactor.cpp	Replace Vector(1)/Matrix init
gtsam_unstable/slam/tests/testRelativeElevationFactor.cpp	Replace Vector(1) expected init
gtsam_unstable/slam/tests/testProjectionFactorPPPC.cpp	Replace expected Jacobian matrices init
gtsam_unstable/slam/tests/testProjectionFactorPPP.cpp	Replace expected Jacobian matrices init
gtsam_unstable/slam/tests/testPartialPriorFactor.cpp	Replace measurement Vector init
gtsam_unstable/slam/tests/testMultiProjectionFactor.cpp	Update commented expected Jacobian init
gtsam_unstable/slam/tests/testInvDepthFactorVariant3.cpp	Replace Vector3 expected + retract deltas
gtsam_unstable/slam/tests/testInvDepthFactorVariant2.cpp	Replace Vector3 expected + retract deltas
gtsam_unstable/slam/tests/testInvDepthFactorVariant1.cpp	Replace Vector6 expected + retract deltas
gtsam_unstable/slam/tests/testInvDepthFactor3.cpp	Replace Vector5 init
gtsam_unstable/slam/tests/testInertialNavFactor_GlobalVelocity.cpp	Replace measurement gyro vector init
gtsam_unstable/slam/tests/testAHRS.cpp	Replace matrices init with braces
gtsam_unstable/slam/RelativeElevationFactor.cpp	Replace Vector(1) return init
gtsam_unstable/slam/PartialPriorFactor.h	Replace prior_ Vector(1) init
gtsam_unstable/slam/Mechanization_bRn2.cpp	Replace Vector3 init with braces
gtsam_unstable/slam/InvDepthFactorVariant3.h	Replace Vector(1) return init
gtsam_unstable/slam/InvDepthFactorVariant2.h	Replace Vector(1) return init
gtsam_unstable/slam/InvDepthFactorVariant1.h	Replace Vector(1) return init
gtsam_unstable/slam/InvDepthFactor3.h	Replace Vector(1) return init
gtsam_unstable/slam/InertialNavFactor_GlobalVelocity.h	Replace ENU/NED matrices + vectors init
gtsam_unstable/slam/EquivInertialNavFactor_GlobalVel.h	Replace ENU/NED matrices + vectors init
gtsam_unstable/slam/EquivInertialNavFactor_GlobalVel_NoBias.h	Replace ENU/NED matrices init
gtsam_unstable/slam/BetweenFactorEM.h	Replace returned Vector(2) init
gtsam_unstable/slam/AHRS.cpp	Replace gravity vector + matrices init
gtsam_unstable/nonlinear/tests/testParticleFactor.cpp	Replace State(Vector) init
gtsam_unstable/nonlinear/tests/testConcurrentIncrementalSmootherGN.cpp	Replace noise sigma vector init
gtsam_unstable/nonlinear/tests/testConcurrentIncrementalSmootherDL.cpp	Replace noise sigma vector init
gtsam_unstable/nonlinear/tests/testConcurrentIncrementalFilter.cpp	Replace noise sigma vector init
gtsam_unstable/nonlinear/tests/testConcurrentBatchSmoother.cpp	Replace noise sigma vector init
gtsam_unstable/nonlinear/tests/testConcurrentBatchFilter.cpp	Replace noise sigma vector init
gtsam_unstable/navigation/tests/testEqVIOSymmetry.cpp	Replace SO3 expmap vectors init
gtsam_unstable/navigation/tests/testEqVIOGroup.cpp	Replace matrices/vectors init
gtsam_unstable/navigation/EqVIOSymmetry.cpp	Replace static Matrix32 init
gtsam_unstable/linear/tests/testQPSolver.cpp	Replace VectorValues/Matrix init
gtsam_unstable/linear/tests/testLinearEquality.cpp	Replace HessianFactor/VectorValues init
gtsam_unstable/linear/LinearInequality.h	Replace Vector(1) rhs init + formatting
gtsam_unstable/geometry/tests/testPose3Upright.cpp	Replace Vector delta init
gtsam_unstable/geometry/tests/testInvDepthCamera3.cpp	Replace Vector5/Vector init
gtsam_unstable/geometry/SimWall2D.cpp	Replace retract delta Vector init
gtsam_unstable/geometry/SimPolygon2D.cpp	Replace retract delta Vector init
gtsam_unstable/geometry/InvDepthCamera3.h	Replace Jacobian block Matrix init
gtsam_unstable/geometry/BearingS2.cpp	Replace Matrix init + add Vector include
gtsam_unstable/examples/ConcurrentCalibration.cpp	Replace sigma Vector init
gtsam_unstable/dynamics/VelocityConstraint3.h	Replace Vector(1) return init
gtsam_unstable/dynamics/tests/testSimpleHelicopter.cpp	Replace matrices/vectors init
gtsam_unstable/dynamics/tests/testPoseRTV.cpp	Replace vec_init Vector init
gtsam_unstable/dynamics/SimpleHelicopter.h	Replace f_ext Vector init
gtsam_unstable/dynamics/PoseRTV.cpp	Replace retract/rot_rates/drag vector init
gtsam_unstable/dynamics/Pendulum.h	Replace Vector(1) return init
gtsam_unstable/base/tests/testFixedVector.cpp	Replace Vector init
examples/SelfCalibrationExample.cpp	Replace calNoise sigma Vector init
examples/Pose3SLAMExampleExpressions_BearingRangeWithTransform.cpp	Replace noise sigma vectors init
examples/Pose3SLAMExample_initializePose3Gradient.cpp	Replace prior variances vector init
examples/Pose3SLAMExample_initializePose3Chordal.cpp	Replace prior variances vector init
examples/Pose3SLAMExample_g2o.cpp	Replace prior variances vector init
examples/Pose3Localization.cpp	Replace prior variances vector init
examples/Pose2SLAMExample_graph.cpp	Replace noise sigma Vector init
examples/LocalizationExample.cpp	Replace Jacobian Matrix + error Vector init
examples/LeggedEstimatorReplayExample.cpp	Replace covariance diagonal Vector init
examples/IMUKittiExampleGPS.cpp	Replace BodyP Vector6 init
examples/ImuFactorsExample.cpp	Replace pose noise sigma Vector init
examples/CombinedImuFactorsExample.cpp	Replace pose noise sigma Vector init
examples/GaussianProcessWnoaSE3Example.cpp	Replace Eigen vector init for diagonal/cmd
examples/elaboratePoint2KalmanFilter.cpp	Replace Vector2 sigma init
doc/Code/LocalizationFactor.cpp	Replace Matrix23 + error Vector init

[dellaert]

Also reviewed locally with Luna; findings:

• Compile blocker: testOptionalJacobian.cpp (line 61). Changing kTestMatrix from dynamic Matrix to Matrix23 makes existing assert_equal calls ambiguous. make -j6 testOptionalJacobian.run fails.
• Correctness/allocation issue: testGeneralSFMFactor_Cal3Bundler.cpp (line 312). A dynamic Vector is initialized with three inner lists, producing a visible 3×1 vector—not the intended 9-vector. Use Vector9{...}; that also avoids a heap allocation.
• Avoidable dynamic temporary: timePose2.cpp (line 62) assigns dynamic Matrix{{...}} to fixed OptionalJacobian<3,3>. Use Matrix3{{...}} or fill *H1 directly.
• Similar missed opportunities exist in InvDepthCamera3.h (line 91) and AHRS.cpp (line 68): fixed-size Jacobian/matrix/vector types are known and should be used.

The brace initializer itself is neutral: dynamic Eigen types allocate once, while fixed types store coefficients inline. The important policy is type selection and avoiding fixed/dynamic conversions at API boundaries.

We could add a short “Eigen fixed vs. dynamic storage” section to DEVELOP.md under Coding Conventions:

• Use fixed MatrixMN/VectorN when dimensions are compile-time known, especially OptionalJacobian outputs.
• Use Matrix/Vector for runtime-sized data or legacy APIs that explicitly require dynamic matrices.
• Prefer direct writes or fixed-size temporaries when assigning to fixed Jacobians.
• Use flat initializer lists for vectors; nested lists are for matrices.