# Tagged Questions

Questions on position tracking, especially using Mathematica coordinate tracking functions and control objects such as Locator, LocatorPane, and ClickPane.

237 views

### Locator Appearance

I am using LocatorPane with LocatorAutoCreate -> True. I would like to have the appearance of each new locator be different. ...
196 views

### Circumnavigating a curve or going through it to show different behavior

I am not sure if what I want to do is possible in Mathematica. I've provided something simple below to convey what I want to do. Basically what I want to happen is that when the ...
411 views

### How to dynamically update Locator[] constraints?

I need to visualize Menelaus' theorem for a triangle with moving locators for each of six points. So the vertexes of the triangle can move in any possible way, and the three points on the sides of the ...
129 views

### Constrain Locator to specified region

How can I constrain the locator to stay within the region defined by RegionPlot? When the Locator remains within the region, ...
187 views

### Different actions with dragging and clicking points in same graphic

On a graphic (in this example a simple plot), I need two points to move when I drag with the mouse, and these points must move to location {1,1} when I click on them. This is how I got it to work, ...
208 views

### Using absolute locator coordinates in Manipulate

In this simplified code below, I'd like to display two plots within Manipulate, and use the Locator controltype to set the value ...
68 views

### A locator that is visible only when it is used

I want to construct a graphics with a locator on top of it. This locator normally has to be invisible, but when I click somewhere in the graphics, the least that has to happen is that the locator ...
102 views

### Locator-based abscissa ranges widget

I'm trying to implement a widget that will enable users to graphically determine certain abscissa ranges in a 2D plot. I've started by coding a prototype, whose output looks like this: The idea ...
169 views

### Using the mouse coordinates to index a matrix

I would like to "write" on to a matrix using the mouse. That is, I would like to use the integer value of Locator coordinates (p) to index a matrix. Then, if the mouse button is down, write a 1 in ...
390 views

### Using Locators in a non-standard Manipulate code

I'm trying to adapt Nasser's method for using a control variable inside Manipulate to selectively choose what part of the code should be recalculated depending on the controls changed (see this ...
662 views

### Constrain movement of a locator inside Manipulate

Once again a big thank you for the great help in my earlier post: Plotting function with Dynamic parameter. It totally worked out. I now have a new coding problem ...
763 views

### How to align dynamic graphics and an image within an Overlay?

I have dynamic graphics over an image but they won't line up, what am I doing wrong? ...
719 views

### How do I draw a credible velocity vs. time graph using Locators?

This is partly a math question, partly a Mathematica question. For educational purposes, I'm making a simple demonstration to create a velocity over time graph from six locators. On the basis of ...
528 views

### Draw plot with locator & slider

I would like to create a plot whereby both the slider and the locator 'draw' the plot. In the following code, the locator & the slider act independently: ...
157 views

### Overlaying location pointer on to a png file

So I have started off with importing a png image of size $512\times 1024$ px. I have then created two locators as demonstrated on the Wolfram tutorials: ...
212 views

### Clicking to add/remove a Locator

I would like to add a Locator to a figure displayed by Manipulate when I click inside the figure, at the location where I click, ...
192 views

### Layers of Locators of Different Colors?

I am a Mathematica novice trying to do some interactive segmentation of microscopy images. I've been trying to understand and build upon some code from a previous StackExchange discussion (Can ...
376 views

### How do I use Mathematica as a vector drawing program?

Recently I changed my furniture in my room and I am trying to find the best position of each part. I am sure that Mathematica could help! I read the LocatorPane, selecting multiple Locators for ...
145 views

### Moving a locator based on the movement of another

My problem is: I want two Locators to simulate a vector in the following sense: The first Locator is the base and the second ...
47 views

### Context-aware Locator

I'm trying to use a Locator for some image processing tasks. Unfortunately, the images we're using have a high dynamic range of low-frequency black and white ...
156 views

### How to restrict the motion of a Manipulate-generated Locator along a line?

If one uses a stand-alone locator and needs it to only be movable along a curve, say, defined by a function f[x], one can use a simple construct: ...
184 views

### Change locator object appearance inside Manipulate

I have read earlier discussions of changing Locator appearance in Manipulate. I would like to change the rendered size of the locator object based on one of the manipulate variables. I can't get ...
167 views

### Manipulate a 2D point controlled simultaneously by Locator and its coordinates

I'm trying to have a point in the plane which can be manipulated both using Locator as well as inserting its $x$ and $y$ coordinates. My attempts at doing this are: ...
257 views

### EventHandler Not Detecting KeyDown

I am trying to use EventHandler to detect KeyDown within a LocatorPane. Anytime I press a key inside the LocatorPane the proper action is not executed (doesn't matter which key I choose) but rather ...
122 views

### Export LocatorPane as image by button

How to Export LocatorPane as image by button or at least by something else? Kuba, thank you! Your method works in a simple case: ...
83 views

### Constrain movement of Locator (increased t-value)

Continuing with the code at the end this topic, I am now searching for a way of constraining the movement of the locator so that it doesn't "jump" from one "part" of the graph of f to another. So, if ...
132 views

### Locator and manipulate

How can I achieve that the points on a Graphics element could be manipulated both by Locators (clicking and moving) and on the Manipulate panel as well. As you can see, only one of the methods work. ...
864 views

### Locator to show coordinates of plot

Old I would like to make the locator follow a plot, giving the coordinates as it moves. I don't really know where to start with this one, but I would like the dynamic plot to look something like ...
85 views

### Avoiding RandomVariate update with use of Locator

I am preparing an activity that simulates the response from a noisy spectrometer. The function I use to generate the data has the form: ...
192 views

### Change the behaviour of a LocatorPane

Normally, LocatorPane detects any single click as in the following example: ...
178 views

### Manipulating several values from the same interval

Some of my calculations depend on the choice of several values from the interval [-2, 2] (it is more or less interpolation of a fixed function using the points as parameters). I want to create a ...
181 views

### How to do dynamic range selection for data fitting in Log plot?

In linear plot, this can be achived by Locator like this: http://mathematica.stackexchange.com/a/24935/13580 ...
113 views

### Manipulating horizontal and vertical 'guidelines'

Is it possible to create an interactive plot that has drag-down / across horizontal & vertical guides a la Illustrator / InDesign? I would like to generate something like this: I would ideally ...
142 views

### Creating a function takes a list and dynamically modifies that list [duplicate]

I'm trying to create a function that uses a dynamic locatorpane to populate a list with the coordinates of user defined locators (added by alt+clicking). This code works fine: ...
93 views

### Interacting with the vertices of a polygon and points on a circle

I want to create an interactive module, where I can plot the vertices of polygon and some points on a circle(for example, suppose a triangle and 3 points on the circle) and move the vertices of the ...
77 views

### How-to let user define a set of VertexCoordinates in a Graph

Here is a simple code I wrote to visualize what I am trying to achieve: C.1 ...
137 views

### How do I constrain movement for lists of Locators using 2nd argument of Dynamic?

I need to display edge labels of a graph in a way that allows the edge labels to be moved. Locator seems the simplest and most obvious function to use. My ...
110 views

### Constrain movement of Locator

Continuing the discussion started in the thread here, I've tried to recreate the code from scratch. I thus looked to constrain the movement of a locator to the graph defined by ...
50 views

### How to use locator continuously with grid of graphics

I am trying to find out, how to properly use a locator continuously within manipulate and a grid of graphics. I have the following example out of this code ...
47 views

### Disable locator-removal in LocatorPane

is there a way to DISABLE the ability to remove points with ALT-click (APPLE-click) from a locator pane? I'm writing a code that allows users to manually label objects in an image by connecting two ...
218 views

### Control multiple locators along a plot

Update 1 @ Michael E2, my effort - for what it is worth!: ...
79 views

### How to draw Locator on circle[{m,n},r]? [closed]

I want to draw Locator on circle[{m,n},r]. The follwing point p is free Locator. How to draw Locator on Circle[{m,n},r] ? ...
149 views

### Enabling/disabling individual locators within a Manipulate

This post helped me out somewhat but it is missing a piece that I really need for something that I am working on that's more complex than what I've shown below. I want to disable a ...
257 views

### Using Manipulate with a control variable for selective recalculation

I'm trying to adapt Nasser's method for using a control variable inside Manipulate to selectively choose what part of the code should be recalculated depending on the controls changed. I've also read ...
88 views

### Hide output from when mouseover Locator graphic

When the mouse pointer passes over the Locator graphic (or one clicks at any point in the frame), the underlying equation that generates the ContourPlot is visible ...
174 views

### Behaviour of Locator

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 ...
99 views

### Attaching functions to movable locators

I'm trying to create a manipulate plot showing the electric field due to a collection of point charges. At the moment I've created such a plot which allows the x and y positions of each charge to be ...
150 views

### Two-way locator & slider controls

I was wondering whether it was possible to have a two way control system, whereby one could click and drag both the locator (which would in turn move the sliders), AND click & drag the sliders ...