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Apply Focus-Glue-Context Fisheye transformations

Source: R/fisheye_fgc.R
fisheye_fgc.Rd

Transforms 2D coordinates using a Focus–Glue–Context (FGC) fisheye transformation. The function expands points inside a focus region, compresses points in a glue region, and leaves the surrounding context unchanged. Optionally, a rotational "revolution" can be added to the glue region to produce a swirling effect.

Usage

fisheye_fgc(data, ...)

Arguments

data

Data on which to perform a focus-glue-context transformation.

...

Additional arguments passed to specific methods. See fisheye_fgc.matrix() and fisheye_fgc.sf() for details for the methods provided by this package.

Details

This is a generic S3 function to perform the focus-glue-context transformation on different types of data.

This function operates in three radial zones around a chosen center:

  • Focus zone (r <= r_in): expands distances from the center using zoom_factor, but does not exceed the r_in boundary.

  • Glue zone (r_in < r <= r_out): compresses distances using a power-law defined by squeeze_factor, then remaps them to smoothly connect focus and context zones.

  • Context zone (r > r_out): coordinates remain unchanged.

Optionally, points in the glue zone can be rotated (revolution) to emphasize continuity.

For the specifics of methods for spatial objects, see fisheye_fgc.sf(). For the underlying mathematical transformation, see fisheye_fgc.matrix().

See also

fisheye_fgc.sf()

fisheye_fgc.matrix()