Plotting Distances of Points in JfreeChart - jfreechart

I need help in Plotting the Distance of points on Scatter Plot and My Array consist of values whose distances are needed to be calculated.
A1-(0.3883,0.4197)
A2-(0.3960,0.3836)
A3-(0.4065,0.4032)
The Distance between A1,A2 is 0.0369 and the distance between A1,A3 is 0.0245 and similarly the Distance between A2,A3 is 0.0221.
My question is how to Plot this Distances(0.0369 of(A1,A2),0.0245 of(A1,A3)..) of that paired values on a Scatter Plot(JfreeChart)?. Please give me Some suggestions on how to a approach this Problem.

As your data model is a graph, I'd look at JGraph, which has better support for labeled edges.
In JFreeChart, you could add an item label or tool tip generator to the XYLineAndShapeRenderer. The generator would have to query your data model for the relevant edge value. You could arrange for your data model to implement TableModel and use a JTable as an ancillary display, as shown in CrosshairDemo1 & 2.

Related

How to mark some grid points on netcdf map?

I can make 2D dimensional netcdf maps of some quantity. I open it in panoply and there is color map of that quantity. But I cannot visualize some boolean value.
Can I somehow mark particular grid points with some symbol on the map (it can be diamond, square, triangle... whatever), is there a way how to do it in Fortran90? I accept also python related help.
Again: I mean there would be color map (from real values) (which I can do) and at the same time some values will have e. g. triangle on it.
If I understand the question correctly, then you can easily do that with Python and using some plotting library (e.g Matplotlib). With Fortran it is extremely tricky as it does not natively support plotting in my mind.
Basically with Python you just have to :
read the wanted variables (coordinates and the field itself)
make the map of the field i.e make the plot
find the locations you want to highlight and just add those locations to the plot

Leaflet JS: Custom 2D projection that uses meters instead of lat,long

I am working on a custom game map. This map is basically a raster image, overlayed with some paths and markers. I want to use Leaflet to display the map.
What I am struggling with, is that Leaflet uses Latitude and Longitude to calculate positions, while it uses meters for distances (path lengths, radii of circles, etc).
This is very understandable when dealing with a spherical world like our Earth, but it complicates the custom map, which is flat a lot.
I would like to be able to specify the positions in the same unit as the distances.
Now, by default Leaflet uses a Spherical Mercator projection. According to the Docs, it is possible to define your own projections and coordinate reference systems, but I have been unable to do this thus far.
How would this be possible? Or is there a simpler way?
You should take a look at the simple coordinate reference system (L.CRS.Simple) included with Leaflet:
A simple CRS that maps longitude and latitude into x and y directly. May be used for maps of flat surfaces (e.g. game maps).
You can define the CRS of your L.Map instead upon initialization like so:
new L.Map('myDiv', {
crs: L.CRS.Simple
});
Some further elaboration: As #ghybs pointed out in the comment below and the comment to your question the default sperical mercator projection (L.CRS.EPSG3857) already works in meters. When you calculate the distance between two coordinates, Leaflet returns meters, example:
var startCoordinate = new L.LatLng(0, -1);
var endCoordinate = new L.LatLng(0, 1);
var distance = startCoordinate.distanceTo(endCoordinate);
console.log(distance);
The above will print 222638.98158654713 to your console which is the distance between those two coordinates in meters. Problem is that when using spherical projection, distance between two coordinates will become less the further you get from the equator which will become problematic when creating a flat gameworld. That's why you should use L.CRS.Simple, you won't have said problem.

C3.js Dynamically add details to legend

I would like to ask whether it is possible to dynamically add text below legend, using C3.js and Angular. I have created a graph that looks like this:
This graph is part of a project that implements linear and polynomial regression.
As you can see, at the left edge of the graph I have managed to show the Rsquared value, using an older answer found in :Add a title to C3.js chart legend
Now what I want is to also display some other information about the graph, such as the array of coefficients used for every selected regression type and the equation formula, below Rsquared. Since the user will be able to choose different regression types, the coefficients length will vary accordingly.
Is it possible to add these info dynamically, to come up with something like:
Rsquared: 0.1234567
a: 290.08505759457904
b: 10.349760852957772
.....{c:....d:...}
Equation: y=ax+b || y=ax+bx+c ||.....
My available data is in the following format:
coefficients [290.08505759457904,10.349760852957772]
equation {a: 290.08505759457904,
b: 10.349760852957772}
Any help would be appreciated. Thanks!

Displaying an Elevation grid in ParaView

I'm new to ParaView and completely lost with all the different data formats. All I want to do is display an elevation grid which is produced by a program. I store the elevation grid in a two dimensional array of floats which is indexed by x and y coordinates and stores the z coordinate. In other words elevationGrid[x][y] stores the height above the point (x, y).
Which file format should I use for this and how is it defined? It would be ideal if someone could give an example file for, say, a 3x3 grid.
A first approach with a 5x5 grid and equation z = x^2+y^2, using a very simple input format. This is a general approach, not especially dedicated to structured grid.
The following has been done with Paraview 3.14.1.
1) Save your data in csv format, i.e. :
"x","y","z"
-0.5,-0.5,0.5
-0.30000001,-0.5,0.34000001
-0.1,-0.5,0.26
[...]
0.1,0.5,0.26
0.30000001,0.5,0.34000001
0.5,0.5,0.5
2) Open in Paraview your csv file
Fill the required import options.
3) Convert your table to geometrical points
Apply Filters > Alphabetical > Table to points
You will be asked to give each variables for each coordinates.
4) Display 3D view to see your points
Create a new visualization view (add a new tab) and choose "3D View".
Activate your TableToPoints filter clicking on the little eye near its name in the pipeline.
If evething is okay, at this point you will see your scatter plot.
5) Last step: create a surface
Apply Filters > Alphabetical > Delaunay 2D
And using default options, one finally obtains:
EDIT:
I remember the name of the dedicated function to create elevation map... It is the Wrap by scalar function. You can combine it with some above steps to get more easily what you want. I could give you an example if necessary.

Information Modeling

The sensor module in my project consists of a rotating camera, that collects noisy information about moving objects in the surrounding environment.
The information consists of distance, angle and relative change of the moving objects..
The limiting view range of the camera makes it essential to rotate the camera periodically to update environment information...
I was looking for algorithms / ways to model these information, in order to be able to guess / predict / learn motion properties of these object..
My current proposed idea is to store last n snapshots of each object in a queue. I take weighted average of positions and velocities of moving object, but I think it is a poor method...
Can you state some titles that suit this case?
Thanks
Kalman {Extended, unscented, ... } filters and particle filters only after reading about Kalman filters.
Kalman filters learn and predict the correct data from noisy data with a Gaussian assumption, so it may be of use to you. If you need non-Gaussian methods, look at the particle filter.

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