Skip to main content

programming - Can individual locators in LocatorPane be temporarily disabled?


This follows up on another question about the sensitivity of Locators in a a LocatorPane.


I would like to be able to enable/disable individual locators in a LocatorPane. In the simplified version of the applet, pictured below, I would like to be able to disable the locators that set the slope of the red line, while allowing the locators that set the slope of the blue line to remain enabled.


locators



Using individual Locators, rather than a LocatorPane, is not an option. (There are some subtle issues that arise with individual locators. Essentially, multiple Locators can behave in a "flaky" fashion in complex applets, in ways that LocatorPane does not.)


Code below:


Manipulate[m = 15;
LocatorPane[Dynamic[pts],
Dynamic[ Module[{x = pts[[1, 1]], y = pts[[2, 2]], x2 = pts[[3, 1]], y2 = pts[[4, 2]]},
Graphics[{
{Blue, Line[{-m*{x2, y2}, m*{x2, y2}}]},
Line[{{x2, 0}, {x2, y2}}], Line[{{x2, y2}, {0, y2}}],
{Red, Line[{-m*{x, y}, m*{x, y}}]},
Line[{{x, 0}, {x, y}}], Line[{{x, y}, {0, y}}]},

PlotRange -> m, Axes -> True, ImageSize -> {300, 300}]]],
{{{-m, 0}, {m, 0}, {1, 0}},
{{0, -m}, {0, m}, {0, 1}},
{{-m, 0}, {m, 0}, {1, 0}},
{{0, -m}, {0, m}, {0, 1}}},
Appearance -> {Automatic, Automatic, Automatic, Automatic}],
{{pts, {{6, 0}, {0, 9}, {3, 0}, {0, 7}}}, ControlType -> None}]

The visibility of the locators can be individually controlled by toggling the respective locator's Appearance between None and Automatic. But even when the locator is invisible (i.e. Appearance -> None) it continues enabled. For example, the red sliders will continue to set the slope of the red line.


A possible solution would be to obtain the Appearance setting of the red sliders and make the assignment of x and y contingent on the Appearance setting.




Answer



A simple way to do this is to change the Dynamic so that it updates only the points you want to be editable. Here is a very simple demonstration


 pts = {{6, 0}, {0, 9}, {3, 0}, {0, 7}};
updatable = Range@Length@pts;
Button["Fixate point 3", (updatable = {1, 2, 4})]
LocatorPane[Dynamic[pts, (pts[[updatable]] = #[[updatable]]) &],
Dynamic@Graphics[Point /@ pts, PlotRange -> {{-10, 10}, {-10, 10}}]]

Comments

Popular posts from this blog

plotting - Filling between two spheres in SphericalPlot3D

Manipulate[ SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, Mesh -> None, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], {n, 0, 1}] I cant' seem to be able to make a filling between two spheres. I've already tried the obvious Filling -> {1 -> {2}} but Mathematica doesn't seem to like that option. Is there any easy way around this or ... Answer There is no built-in filling in SphericalPlot3D . One option is to use ParametricPlot3D to draw the surfaces between the two shells: Manipulate[ Show[SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], ParametricPlot3D[{ r {Sin[t] Cos[1.5 Pi], Sin[t] Sin[1.5 Pi], Cos[t]}, r {Sin[t] Cos[0 Pi], Sin[t] Sin[0 Pi], Cos[t]}}, {r, 1, 2 - n}, {t, 0, Pi}, PlotStyle -> Yellow, Mesh -> {2, 15}]], {n, 0, 1}]

plotting - Plot 4D data with color as 4th dimension

I have a list of 4D data (x position, y position, amplitude, wavelength). I want to plot x, y, and amplitude on a 3D plot and have the color of the points correspond to the wavelength. I have seen many examples using functions to define color but my wavelength cannot be expressed by an analytic function. Is there a simple way to do this? Answer Here a another possible way to visualize 4D data: data = Flatten[Table[{x, y, x^2 + y^2, Sin[x - y]}, {x, -Pi, Pi,Pi/10}, {y,-Pi,Pi, Pi/10}], 1]; You can use the function Point along with VertexColors . Now the points are places using the first three elements and the color is determined by the fourth. In this case I used Hue, but you can use whatever you prefer. Graphics3D[ Point[data[[All, 1 ;; 3]], VertexColors -> Hue /@ data[[All, 4]]], Axes -> True, BoxRatios -> {1, 1, 1/GoldenRatio}]

plotting - Mathematica: 3D plot based on combined 2D graphs

I have several sigmoidal fits to 3 different datasets, with mean fit predictions plus the 95% confidence limits (not symmetrical around the mean) and the actual data. I would now like to show these different 2D plots projected in 3D as in but then using proper perspective. In the link here they give some solutions to combine the plots using isometric perspective, but I would like to use proper 3 point perspective. Any thoughts? Also any way to show the mean points per time point for each series plus or minus the standard error on the mean would be cool too, either using points+vertical bars, or using spheres plus tubes. Below are some test data and the fit function I am using. Note that I am working on a logit(proportion) scale and that the final vertical scale is Log10(percentage). (* some test data *) data = Table[Null, {i, 4}]; data[[1]] = {{1, -5.8}, {2, -5.4}, {3, -0.8}, {4, -0.2}, {5, 4.6}, {1, -6.4}, {2, -5.6}, {3, -0.7}, {4, 0.04}, {5, 1.0}, {1, -6.8}, {2, -4.7}, {3, -1.