isgraphics

True for valid graphics object handles

Syntax

tf = isgraphics(H)

tf = isgraphics(H,type)

Description

tf = isgraphics(H) returns true for elements of H that are valid graphics objects and false where elements are not valid graphics objects or are graphics objects that have been deleted.

tf = isgraphics(H,type) returns true for elements of H that are valid graphics objects of the type specified by the type argument. An object type is the value contained in the object’s Type property.

Examples

Test for Valid Handles

Create a plot and return the handle array. Test array for valid handles.

H = plot(rand(5));

isgraphics(H)

ans = 5x1 logical array

   1
   1
   1
   1
   1

Test for Handle Types

Create a plot and return the handle array. Concatenate with other graphics objects and test for handles that are of type Line.

H = plot(rand(5)); 

a = [H;gca;gcf]; 
isgraphics(a,'line')

ans = 7x1 logical array

   1
   1
   1
   1
   1
   0
   0

Input Arguments

H — Input variable or expression

graphics object array

Input variable or expression that evaluates to graphics object handles.

type — Object type

character vector | string scalar

Object type, specified as a character vector or string scalar. An object’s type is the value of its Type property.

Output Arguments

tf — Result

logical array

Result, returned as a logical array. Values of 1 indicate elements of the input array that are valid, and values of 0 indicate elements that are invalid. The result is an empty array when the input array is empty.

Version History

Introduced in R2014b

R2024b: Passing multidimensional array as input returns output of same size

Passing an array that has three or more dimensions as input returns an array of the same size. Previously, isgraphics returned a 2-D array when the input had three or more dimensions. The higher dimensions were collapsed into the second dimension. For example, if the input was a 2-by-4-by-5 array, the output was a 2-by-20 array.

If you pass a scalar, 1-D, or 2-D array to either function, the output is the same size as in previous releases.

If you use nested calls to the all or any function, update your code to use the "all" argument instead of the nested function call to preserve the shape of the output.

For example, this code returns a scalar logical value in R2024a. In R2024b, it returns a 1-by-1-by-4 array of logical values.

h = gobjects(2,3,4);
all(all(isgraphics(h)))

To preserve the scalar output, call the all function once with the "all" argument. The result is a scalar logical value.

h = gobjects(2,3,4);
all(isgraphics(h),"all")