Specialist Department: MATLAB & Simulation

→ 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

Reference Files

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