Main Content


Create rectangularly bounded drag constraint function

makeConstrainToRectFcn is not recommended. With the new ROIs, use the DrawingArea property instead. For more information, see Compatibility Considerations.



fcn = makeConstrainToRectFcn(roi,x,y) creates a position constraint function for draggable tools of a given ROI type. The position of the tool is constrained by rectangular boundaries described by position vectors x and y.


collapse all

Display an image.


Create an impoint object at the (x,y) coordinate (20,60). In an image, the positive y direction is downwards.

h = impoint(gca,20,60);

Make a function that constrains the impoint to the image limits.

x = get(gca,'XLim');
y = get(gca,'YLim');
fcn = makeConstrainToRectFcn('impoint',x,y);

Apply the constraint function to the impoint. Try dragging the point past the boundary of the image. The constraint function prevents the point from crossing the image boundary.


Input Arguments

collapse all

ROI type, specified as 'imellipse', 'imfreehand', 'imline', 'impoint', 'impoly', or 'imrect'.

Data Types: char | string

Rectangular boundaries in the x direction, specified as a 2-element numeric vector of the form [xmin xmax].

Rectangular boundaries in the y direction, specified as a 2-element numeric vector of the form [ymin ymax].

Output Arguments

collapse all

Function handle, returned as a handle. For more information, see Create Function Handle.

Version History

Introduced in R2006a

expand all