Behaviour of Locator

Question

I seek advice regarding the constrained behaviour of the Locator: appears confined to square {0,0}->{1,1}. When I change starting position it snaps to this constrained region.

The code I am referring to follows:

Manipulate[
 Module[{cn, d}, cn = {c1, c2, c3}; 
  d = Norm[# - pt] & /@ {c1, c2, c3}; 
  Graphics[{{Black, Point[cn]}, 
    MapThread[{#1, Circle[#2, #3]} &, {{Red, Green, Blue}, cn, d}]}]
  ],
 {pt, {1, 1}, ControlType -> Locator, LocatorRegion -> Full},
 Initialization -> (c1 = {0, 0}; c2 = {3, 0}; c3 = {0, 3};)
 ]

The constraint remains whether I define PlotRange, use EuclideanDistance or otherwise define the distance function.

The following graphic shows (obviously) this is well defined outside the region of constraint of the Locator. Intersection point at {4,4}with fixed points at{0,0}, {1,0}, {0,1}.

Image generated by:

Graphics[{{Black, Point[cc = {{0, 0}, {1, 0}, {0, 1}}]}, {Red, 
   Point[{{4, 4}}]}, Map[Circle[#1, Norm[# - {4, 4}]] &, cc]}]

---

I can get around the constraint using Slider2D but I am still uncertain about the Locator issue.

Manipulate[
 Module[{cn, d}, cn = {c1, c2, c3}; 
  d = Norm[# - pt] & /@ {c1, c2, c3}; 
  Graphics[{{Black, Point[cn]}, {Red, PointSize[0.02], Point[pt]}, 
    MapThread[{#1, Circle[#2, #3]} &, {{Red, Green, Blue}, cn, d}]}, 
   PlotRange -> {{-5, 5}, {-5, 5}}]
  ],
 {pt, {-4, -4}, {4, 4}, ControlType -> Slider2D},
 Initialization -> (c1 = {0, 0}; c2 = {1, 0}; c3 = {0, 1};)
 ]

Thank you @Nasser I look forward to trying your code.

Answer 1

I've have not used Locator for a while. But please try this (I am not sure if this is what you asking about either, but this makes the locator free to move anywhere in the PlotRange given in the Graphics), if this is not what you meant, will delete this

Manipulate[
 Module[{cn = {c1, c2, c3}, d},
  d = Norm[# - pt] & /@ cn;
  Graphics[{
    {Black, Point[cn]},
    MapThread[{#1, Circle[#2, #3]} &, {{Red, Green, Blue}, cn, d}
     ]
    }, PlotRange -> {{-6, 6}, {-6, 6}},
   Axes -> True]
  ],
 {{pt, {1, 1}}, Locator},
 Initialization :> 
  (c1 = {0, 0};
   c2 = {3, 0};
   c3 = {0, 3};
   )
 ]