How to doc() a command which is overloaded by multiple toolboxes

The evaluate() command has a version in both the the Curve Fitting Toolbox and in the Optimization Toolbox. How does one use doc() to resolve the ambiguity and bring up the documentation of the desired version?

Answer 1

[Steven Lord]

The evaluate function in both those products (and a few others) is a method of different types of objects.

which -all evaluate

evaluate is a built-in method                                 % matlab.io.xml.dom.Document method
/MATLAB/toolbox/curvefit/curvefit/@fittype/evaluate.m         % fittype method
/MATLAB/toolbox/ident/nlident/@idNeuralStateSpace/evaluate.m  % idNeuralStateSpace method
/MATLAB/toolbox/ident/nlident/@idnlfun/evaluate.m             % idnlfun method
/MATLAB/toolbox/pde/@pdeInterpolant/evaluate.m                % pdeInterpolant method

In Curve Fitting Toolbox, evaluate is a method of the fittype object.

help fittype.evaluate

 EVALUATE Evaluate a FITTYPE object
 
    F = FEVAL(FITOBJ,A,B,...,X) evaluates the function
    value F of FITOBJ with coefficients A,B,... and data X.
 
    [F, J] = FEVAL(FITOBJ,A,B,...,X) evaluates the function
    value F and Jacobian J, with respect to the coefficients,
    of FITOBJ with coefficients A,B,... and data X.

If I used doc fittype.evaluate it will bring up the documentation page for that method. In my MATLAB Online session that method does not have a dedicated function reference page so it brings up the help text instead.

The evaluate method for OptimizationExpression objects didn't show up in my first which call because that class was not loaded in memory at the time I called which. Let me make one and you'll see that now the Optimization Toolbox object methods are listed:

x = optimvar('x');
y = optimvar('y');
prob = optimproblem;
prob.Objective = -x -y/3;
which -all evaluate

/MATLAB/toolbox/curvefit/curvefit/@fittype/evaluate.m                                   % fittype method
evaluate is a built-in method                                                           % matlab.io.xml.dom.Document method
/MATLAB/toolbox/shared/adlib/+optim/+problemdef/@OptimizationExpression/evaluate.p      % optim.problemdef.OptimizationVariable method
/MATLAB/toolbox/shared/adlib/+optim/+internal/+problemdef/@ExpressionForest/evaluate.p  % optim.internal.problemdef.ExpressionForest method
/MATLAB/toolbox/shared/adlib/+optim/+internal/+problemdef/Uminus.p                      % optim.internal.problemdef.Uminus method
/MATLAB/toolbox/shared/adlib/+optim/+internal/+problemdef/Operator.p                    % optim.internal.problemdef.UnaryOperator method
/MATLAB/toolbox/shared/adlib/+optim/+internal/+problemdef/Rdivide.p                     % optim.internal.problemdef.Rdivide method
/MATLAB/toolbox/shared/adlib/+optim/+internal/+problemdef/Minus.p                       % optim.internal.problemdef.Minus method
/MATLAB/toolbox/ident/nlident/@idNeuralStateSpace/evaluate.m                            % idNeuralStateSpace method
/MATLAB/toolbox/ident/nlident/@idnlfun/evaluate.m                                       % idnlfun method
/MATLAB/toolbox/pde/@pdeInterpolant/evaluate.m                                          % pdeInterpolant method

Now if I ask for help:

help optim.problemdef.OptimizationExpression.evaluate

 optim.problemdef.OptimizationExpression/evaluate - Evaluate optimization expression
    Use evaluate to find the numeric value of an optimization expression at
    a point.

    Syntax
      val = evaluate(expr,pt)

    Input Arguments
      expr - Optimization expression
        OptimizationExpression object
      pt - Values of variables in expression
        structure

    Output Arguments
      val - Numeric value of expression
        double

    Examples
      openExample('optim/EvaluateOptimizationExpressionAtPointExample')
      openExample('optim/EvaluateObjectiveFunctionAtSolutionExample')

    See also solve, infeasibility, OptimizationExpression

    Introduced in Optimization Toolbox in R2017b
    Documentation for optim.problemdef.OptimizationExpression/evaluate
       doc optim.problemdef.OptimizationExpression/evaluate

and if I asked for doc on that method name in MATLAB Online it would bring up the page in the online documentation that I linked above.

This is documented in the help and documentation for the doc function. [Which I'd guess is one of the less frequently referenced documentation pages.]

"Some classes and other packaged items require that you specify the package name. Events, properties, and some methods require that you specify the class name. Separate the components of the name with periods, such as:"

Also see the "Class and Method Reference Pages" example on that doc page.