This is a note that on the basis of the algorithm for generating spectra (which was described in the article “The Saltan Spectroscope ...” ) a test service was created that can be addressed by anyone.

Under the cut - instructions for using the service and its capabilities.

The general principles of generating spectra (projections) are given in the article mentioned above. Pictures are somewhat reminiscent of the figures Chladni .

Interface

The service interface is extremely simple, focused on desktop computers and is not adapted for mobile screens.

Generation control is to change the parameters listed on the right side of the screen on the control panel. The control panel is divided into several sections.
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Set of points (Set)

The geometry of the location of the base set of points is set here.



Grid: Grid type. Two types are available - based on regular polygons (Polygon) and based on circles (Radial).

Symm: Type of symmetry, the number of sides of the base polygon. The available range is from a triangle to a 16-gon. With a large number of sides, the pictures of the spectra become hardly distinguishable from each other (polygons turn into a circle).

Size: The size of the side of the polygon. The minimum is 2 (two points). To the right of the size, the total number of spectral lines of this set is indicated in brackets, which is one less than the number of points (since the zero spectrum is excluded).

Border: A parameter that allows you to remove points from the center of the set. In the limit, you can leave only the points on the border (bordering) of the polygon.

The initial set of points is a 6-gon with a side of 10 points.

Function Control

Two parameters are available that affect the generation of the distance function between points.



General view of the function used: $$$F = w * D2 ^ g + 1 / D2 ^ g$,
here $$$D2$- the square of the Euclidean distance between points, $$$w = Distortion ^ 3 / n ^ 2$- the distortion parameter, and $$$g = Degree$- degree.

These parameters allow you to "deform" the basic set, make it convex or concave.

Picture Control (Plot)

There are two parameters.
Type: Determines the output mode - the type of the displayed image. The three types available are points (points), contours (contour) and color fill (fill). This is a key parameter on which the interpretation of others depends.
Nums: The number of simultaneously output spectra. From 1 to 16. When displaying several spectra, you can specify parameters whose indices will also vary linearly with the number of the spectrum. Such parameters are set in the "Spectr" section.

Spectrum Management

Here you can configure three main indexes that affect the display of the spectra: P, Z and S.



To the right of each index name is a check box (checkbox), which determines the participation of the index in the spread, if more than one spectrum is displayed simultaneously. Despite the fact that you can activate all three checkboxes (reversal) at the same time, it is better not to do this, and only vary one index.

P-index: This is the projection number. The total number of available projections is displayed after the back line. For example, the inscription "5/90" means that the current P-index is 5, and a total of 90 different projections are available. The number of projections is the number of degenerate spectra.

Z-index: This index can be viewed as the weight or height of projection points. The index value affects the color distribution of points in the Points mode, or the shape of the contours (areas) in the Contour and Fill modes.

S-index: Another index associated with non-degenerate levels of the spectrum. In Points mode, it affects the distribution of the size of the displayed points. In Contour and Fill modes, the masking of triangulation depends on this index.
Unlike other indexes, the S-index value starts from 0. A zero value means a disabled index (not active).

The total number of available indices Z and S is determined by the number of non-degenerate levels of the spectrum.

Style / Size (Style)

Size: In Points mode, the style parameter determines the size of points. In Contour mode - the number of displayed levels (contours). With a large parameter value, contour generation slows down.

Color Management

Map: Select color palettes (maps). The checkbox inverts the palette.
Alpha: Color saturation value.

A selection of background images is also available. Some spectra sound well against a dark background.

Menu actions

In the current version is available:

• Save : Save the current spectrum parameters.
• Load : Restores the spectrum by previously saved parameters.
• Reset : Reset all parameters to factory settings.

Yes a little. But better than nothing.
You can take spectra and save them as image files on your computer.

Spectra examples

Not all spectra have artistic value. But if you practice a little, you can learn how to get pretty interesting.

Points

When displaying mosaics, the size of the points is fixed, and the color distribution is specified by the Z-index. In the first article, a mosaic pattern was already presented. Here we just unfolded the mosaic on the Z-index:


If you vary the size of the points, then you can get these “laces”:

Contours

An example of very simple contours on a 6-corner basis:


It is their primitiveness that they attract.
If you complicate things a little (add the number of dial points), then you can get something like this:


And on a 10-coal basis, this is:


If you wish, you can always add colors. For example, red 5-point stars for budennovkas:



In general, I have everything. Use and experiment!
I hope, but I do not guarantee that the service will stand. We will correct critical and funny bugs, extension of the functional is in question.

All with the day of knowledge, without which we would not see these pictures!