get (timer)


Display or get timer object properties

Syntax

• get(obj)
  out = get(obj)
  out = get(obj,'PropertyName')
  

Description

get(obj) displays all property names and their current values for timer object obj.

V = get(obj) returns a structure, V, where each field name is the name of a property of obj and each field contains the value of that property.

V = get(obj,'PropertyName') returns the value, V, of the timer object property specified in PropertyName.

If PropertyName is a1-by-N or N-by-1 cell array of strings containing property names, V is a 1-by-N cell array of values. If obj is a vector of timer objects, V is an M-by-N cell array of property values where M is equal to the length of obj and N is equal to the number of properties specified.

Example

• t = timer;
  get(t)
      AveragePeriod: NaN
           BusyMode: 'drop'
           ErrorFcn: []
      ExecutionMode: 'singleShot'
      InstantPeriod: NaN
          LastError: 'none'
               Name: 'timer-1'
             Period: 1
            Running: 'off'
         StartDelay: 0
           StartFcn: []
            StopFcn: []
                Tag: ''
     TasksToExecute: Inf
      TasksExecuted: 0
           TimerFcn: []
               Type: 'timer'
           UserData: []
  get(t, {'StartDelay','Period'})
  ans =
  
      [0]    [1]

getappdata

Get value of application-defined data

Syntax

• value = getappdata(h,name)
  values = getappdata(h)
  

Description

value = getappdata(h,name) gets the value of the application-defined data with the name specified by name, in the object with the handle h. If the application-defined data does not exist, MATLAB returns an empty matrix in value.

value = getappdata(h) returns all application-defined data for the object with handle h.

getenv

Get environment variable

Syntax

• getenv 'name'
  N = getenv('name')
  

Description

getenv 'name' searches the underlying operating system's environment list for a string of the form name=value, where name is the input string. If found, MATLAB returns the string, value. If the specified name cannot be found, an empty matrix is returned.

N = getenv('name') returns value to the variable, N.

Examples

• os = getenv('OS')
  
  os =
  Windows_NT
  

getfield

Get field of structure array

Note getfield is obsolete and will be removed in a future release. Please use dynamic field names instead.

Syntax

• f = getfield(s,'field')
  f = getfield(s,{i,j},'field',{k})
  

Description

f = getfield(s,'field'), where s is a 1-by-1 structure, returns the contents of the specified field. This is equivalent to the syntax f = s.field.

If s is a structure having dimensions greater than 1-by-1, getfield returns the first of all output values requested in the call. That is, for structure array s(m,n), getfield returns f = s(1,1).field.

f = getfield(s,{i,j},'field',{k}) returns the contents of the specified field. This is equivalent to the syntax f = s(i,j).field(k). All subscripts must be passed as cell arrays--that is, they must be enclosed in curly braces (similar to{i,j} and {k} above). Pass field references as strings.

Examples

Given the structure

• mystr(1,1).name = 'alice';
  mystr(1,1).ID = 0;
  mystr(2,1).name = 'gertrude';
  mystr(2,1).ID = 1
  

Then the command f = getfield(mystr,{2,1},'name') yields

• f =
  
  gertrude
  

To list the contents of all name (or other) fields, embed getfield in a loop.

• for k = 1:2
      name{k} = getfield(mystr,{k,1},'name');
  end
  name
  
  name =
  
      'alice'    'gertrude'
  

The following example starts out by creating a structure using the standard structure syntax. It then reads the fields of the structure using getfield with variable and quoted field names and additional subscripting arguments.

• class = 5;     student = 'John_Doe';
  grades(class).John_Doe.Math(10,21:30) = ...
               [85, 89, 76, 93, 85, 91, 68, 84, 95, 73];
  

Use getfield to access the structure fields.

• getfield(grades,{class}, student, 'Math', {10,21:30})
  
  ans =
  
      85    89    76    93    85    91    68    84    95    73
  

getframe


Get movie frame

Syntax

• F = getframe
  F = getframe(h)
  F = getframe(h,rect)
  [X,Map] = getframe(...)
  

Description

getframe returns a movie frame. The frame is a snapshot (pixmap) of the current axes or figure.

F = getframe gets a frame from the current axes.

F = getframe(h) gets a frame from the figure or axes identified by the handle h.

F = getframe(h,rect) specifies a rectangular area from which to copy the pixmap. rect is relative to the lower-left corner of the figure or axes h, in pixel units. rect is a four-element vector in the form [left bottom width height], where width and height define the dimensions of the rectangle.

F = getframe(...) returns a movie frame, which is a structure having two fields:

• cdata - The image data stored as a matrix of uint8 values. The dimensions of F.cdata are height-by-width-by-3.
• colormap - The colormap stored as an n-by-3 matrix of doubles. F.colormap is empty on true color systems.

To capture an image, use this approach:

• F = getframe(gcf);
  image(F.cdata)
  colormap(F.colormap)
  

[X,Map] = getframe(...) returns the frame as an indexed image matrix X and a colormap Map. This version is obsolete and is supported only for compatibility with earlier version of MATLAB. Since indexed images cannot always capture true color displays, you should use the single output argument form of getframe. To write code that is compatible with earlier version of MATLAB and that can take advantage of true color support, use the following approach:

• F = getframe(gcf);
  [X,Map] = frame2im(f);
  imshow(X,Map)
  

Remarks

Usually, getframe is used in a for loop to assemble an array of movie frames for playback using movie. For example,

• for j = 1:n
      plotting commands
      F(j) = getframe;
  end
  movie(F)
  

To create movies that are compatible with earlier versions of MATLAB (before Release 11/MATLAB 5.3) use this approach:

• M = moviein(n);
  for j = 1:n
      plotting commands
      M(:,j) = getframe;
  end
  movie(M)
  

Capture Regions

Note that F = getframe; returns the contents of the current axes, exclusive of the axis labels, title, or tick labels. F = getframe(gcf); captures the entire interior of the current figure window. To capture the figure window menu, use the form F = getframe(h,rect) with a rectangle sized to include the menu.

Examples

Make the peaks function vibrate.

• Z = peaks; surf(Z)
  axis tight
  set(gca,'nextplot','replacechildren');
  for j = 1:20
      surf(sin(2*pi*j/20)*Z,Z)
      F(j) = getframe;
  end
  movie(F,20) % Play the movie twenty times