Find handle objects - MATLAB - MathWorks Deutschland (2024)

FAQs

How do you get the handle of an object in MATLAB? ›

h = gco returns the handle of the current object. h = gco(figure_handle) returns the handle of the current object in the figure specified by figure_handle .

h = findall( objhandles , prop 1, value 1,..., prop N, value N) returns the handles of all objects in the hierarchy that have the specified properties set to the specified values. For example, h = findall(gcf,'Type','text','Color','r') returns all text objects in the current figure that have a red color.

Use the gcf command to get the current figure handle. surf(peaks) fig = gcf; % current figure handle fig.

Use isequal when you want to determine if different handle objects have the same data in all object properties. Use == when you want to determine if handle variables refer to the same object. When comparing objects that contain dynamic properties, isequal always returns false .

Handle objects enable more than one variable to refer to the same object. Handle-object behavior affects what happens when you copy handle objects and when you pass them to functions.

A function handle is a MATLAB^® data type that represents a function. A typical use of function handles is to pass a function to another function. For example, you can use function handles as input arguments to functions that evaluate mathematical expressions over a range of values.

Hmatch = findobj( H ,'-class', class ) finds all objects belonging to the specified class. Hmatch = findobj( H ,'-isa', class ) finds all objects belonging to the specified class.

MATLAB allows you to get any property of a figure handle (or actually any type of graphics handle, including axes, line objects, text objects, and so on) by using the 'get' function in the following manner: >> h = figure; >> propvar = get(h, 'Propertyname');

The findobj function can scan the object hierarchy to obtain the handles of objects that have specific property values. For identification, all graphics objects have a Tag property that you can set to any character vector. You can then search for the specific property/value pair.

Function handles are variables that you can pass to other functions. For example, calculate the integral of x² on the range [0,1]. q = integral(f,0,1); Function handles store their absolute path, so when you have a valid handle, you can invoke the function from any location.

What is the difference between handle and value in MATLAB? ›

Value objects are associated with a specific variable. Handle objects can be referenced by multiple variables. Whether you implement a handle or value class depends on what your class represents and how you want objects to behave. MATLAB^® handle variables support reference semantics.

ht = matlabFunction( f ) converts the symbolic expression or function f to a MATLAB^® function with handle ht . If there is an equivalent MATLAB function operating on the double data type for the symbolic expression or function, then the converted function can be used without Symbolic Math Toolbox™.

B = isvalid( H ) returns a logical array in which each element is true if the corresponding element in H is a valid handle. A handle variable becomes invalid if the object has been deleted. Within a class delete method, isvalid always returns false . You cannot override the isvalid method in handle subclasses.

When comparing two handle objects, use == to test whether objects have the same handle. Use isequal to determine if two objects with different handles have equal property values. When comparing empty object arrays, isequal returns logical 1 ( true ) only when the arrays have the same size and class.

Figure handles. To create a figure, use the figure function like so: >> fhandle = figure; This creates a new figure window and stores all the figure data in the variable fhandle.

mp = findprop( h , property ) returns the matlab. metadata. Property object associated with the named property of the object h . property can be a property defined by the class of h or a dynamic property defined only for the object h .

The handle class implements methods to support events and listeners, destructors, relational operations, and other operations. Handle Class Destructor. Define a delete method to customize what happens when MATLAB destroys handle objects.