dept-matlab

name

dept-matlab

description

Specialist Department: MATLAB & Simulation. Activated when project involves .m/.mlx/.slx files, Simulink models, Stateflow, code generation, fixed-point conversion, or model-based design. Trigger for "MATLAB", "Simulink", "Stateflow", "Embedded Coder", "MATLAB Coder", "fixed-point", "transfer function", "Bode plot", "state-space", "MIL", "SIL", "PIL", "HIL", "model-based design", "code generation", "designfilt", "fft", "ode45", or any MathWorks product or numerical computing context.

Specialist Department: MATLAB & Simulation

Activation

Activates when ANY of: .m, .mlx, .slx, .mdl files detected; MATLAB path setup (startup.m, pathdef.m); toolbox usage; Simulink blocks; Stateflow charts; Embedded Coder configuration; or user explicitly states MATLAB context.

---

Phase Injections Into All Roles

→ Requirements Analyst

Additional NFR categories to capture:

• Numerical accuracy: Tolerance bands for each output signal. Reference comparison method (analytical solution, validated tool, high-fidelity simulation).
• Fixed-point requirements: Word length constraints, overflow strategy (saturate/wrap), precision requirements per signal.
• Code generation targets: Target MCU, execution time budget per step, memory budget, MISRA compliance for generated code.
• Simulation requirements: Solver type (fixed/variable step), step size, simulation duration, real-time factor target.
• Toolbox dependencies: Which MATLAB toolboxes are required (Signal Processing, Control System, Image Processing, etc.).

→ System Engineer

Additional design concerns:

• MATLAB package namespace: Organize code in +pkgname/ packages to avoid name collisions.
• Simulink model hierarchy: Top model → subsystems. Bus naming conventions.
• Signal naming with units: velocity_mps, temperature_degC, pressure_kPa, angle_rad. Every signal name includes unit suffix.
• Parameter naming: maxTorque_Nm, filterOrder, sampleRate_Hz. Include unit.
• Fixed-point scaling strategy: Document scaling for each signal path. Use Fixed-Point Designer to analyze ranges and propose types.
• MIL/SIL/PIL/HIL test levels:
  • MIL: Simulink model tested in Simulink.
  • SIL: Generated C code tested on host.
  • PIL: Generated code on target MCU.
  • HIL: Generated code on target with simulated plant.

→ Backend Developer (MATLAB Developer)

MATLAB coding standards:

• Function headers: H1 line + full help block. Use arguments block (R2019b+) for type and range validation on all public functions.

  function [output] = calculateTrajectory(pos, vel, dt, options)
  %CALCULATETRAJECTORY Compute projectile trajectory with drag.
  %   [POS] = CALCULATETRAJECTORY(P0, V0, DT) computes trajectory...
      arguments
          pos (3,1) double
          vel (3,1) double
          dt (1,1) double {mustBePositive}
          options.dragCoeff (1,1) double {mustBeNonnegative} = 0.47
      end
  

• Vectorize: Prefer vectorized operations over loops. Use arrayfun, bsxfun. Document when loops are intentional (memory, algorithm requirement).
• Pre-allocate: result = zeros(n, m) before loops. NEVER grow arrays in loops.
• No eval/evalin/feval(string): Security risk and prevents static analysis.
• No global variables: Pass data through arguments or object properties.
• eps for float comparison: NEVER if (a == b). ALWAYS if abs(a-b) < tol.
• Use \ not inv(): x = A \ b is numerically stable. x = inv(A) * b is not. Check condition: if cond(A) > 1e12, warning('Ill-conditioned'); end
• Naming: camelCase functions, PascalCase classes, UPPER_SNAKE constants. snake_case for Simulink models, camelCase signals with unit suffix.
• 80 char line max. Wrap with .... 4-space indent. One statement per line.
• Section breaks: %% Section Name to organize scripts.
• Simulink: Run Model Advisor before delivery. Pass MAAB / ISO 26262 / DO-331 checks as applicable. Complete signal naming (no unlabeled wires).

→ Unit Tester

MATLAB testing standards:

• Use matlab.unittest.TestCase with method-based tests.
• Traceability: % Validates FR-001, AC-001-1 comment on every test.
• Numerical assertions: testCase.verifyEqual(actual, expected, 'AbsTol', 1e-10) or 'RelTol', 1e-6. NEVER use exact equality for floating-point.
• Performance: timeit(@() functionToTest(args)) to validate NFR timing budgets.
• Coverage: Use CodeCoveragePlugin for coverage reporting.
• Test NaN/Inf: Verify explicit handling (not silent propagation).
• Test empty inputs: [], {}, empty strings.
• Test ill-conditioned inputs: Near-singular matrices, near-zero denominators.
• Test dimensional correctness: Input/output sizes match specification.
• Simulink testing: sltest.TestCase for model testing. Equivalence testing for MIL vs SIL, SIL vs PIL. Use test harness for each subsystem.

→ Integration Tester

• MIL → SIL equivalence: Same inputs to Simulink model and generated C code → outputs match within tolerance.
• SIL → PIL equivalence: Same inputs on host and target MCU → outputs match.
• Model-level integration: Test subsystem interactions within the top model.
• Hardware integration: If targeting real hardware, test sensor/actuator interfaces.

→ Security Engineer

• No eval, evalc, evalin, feval(string) — injection risk.
• No system() or ! command with user-supplied strings.
• Validate all file paths before fopen, load, save.
• Use matfile or datastore for large data (not load into workspace).
• Handle file I/O errors with try/catch.
• For production generated code: Sign code artifacts, verify authenticity.

→ Documenter

• Document all functions with full MATLAB help block format.
• Simulink models: Document each subsystem purpose in block annotations.
• Include signal flow descriptions for complex models.
• Data dictionary: Document all workspace variables, bus definitions, enumerations.

→ Release Engineer

Additional release artifacts:

• Code generation report (if Embedded Coder used): HTML report from codegen.
• Fixed-point comparison report: Float vs fixed-point results comparison with error analysis.
• MIL/SIL equivalence test report: Showing matching results within tolerance.
• Model Advisor results: Showing all checks passed or documented exceptions.
• Toolbox dependency list: matlab.codetools.requiredFilesAndProducts output.
• MATLAB version and toolbox versions: For reproducibility.

---

Common MATLAB Toolboxes

Toolbox	Use Case
Signal Processing	Filtering, FFT, spectral analysis
Control System	Transfer functions, Bode, root locus
Image Processing	Filtering, segmentation, feature extraction
Statistics & Machine Learning	Regression, classification, clustering
Optimization	Linear/nonlinear solvers, genetic algorithms
Symbolic Math	Analytical solutions, symbolic derivation
Simulink	Dynamic system modeling and simulation
Stateflow	State machines, sequential logic
Embedded Coder	Production C/C++ code generation
MATLAB Coder	General-purpose C/C++ code generation
Simulink Test	Test harness management, equivalence testing
Fixed-Point Designer	Fixed-point conversion and optimization
DSP System	Streaming signal processing
Communications	Modulation, coding, channel models
Aerospace	Flight dynamics, coordinate transforms
Robotics System	Kinematics, path planning, ROS interface
Automated Driving	Perception, planning, vehicle dynamics
Sensor Fusion & Tracking	Kalman filters, multi-object tracking
Deep Learning	Neural networks, training, inference
Computer Vision	Feature detection, object recognition
Radar	Waveform design, target detection

---

Reference Files

• references/numerical-computing.md — Float pitfalls, FFT patterns, filter design, control systems, fixed-point notation, common error fixes.