Small sample map.

<p>Error map depicting 2 fields with trilateration decoding (left), 3 field trilateration (centre) and 3 fields vector average decoding (right). The encoding function is linear for all cases. Each pixel on the map is used as a stimulus point and the distance between the result and original point is denoted by the colour of the pixel. Errors range from 0 to 1 field radius.</p

Response curve comparison.

<p>Response curves for Cosine 0.8, Gaussian 0.4 and Sigmoid 2.4. The input is along the abscissa and the response is along the ordinate.</p

Error plot for a linear transform.

<p>Both S and M maps have identical triangular structure and a one to one transformation space.</p

Border effects.

<p>Encoding accuracy graph showing the effect of large overlaps at the borders, for 10×10 array.</p

Gaussian overlap visualisation.

<p>Input test data and output arrays from experimental software. Each point from the input grid (top left) is encoded using a Gaussian function and decoded using vector averaging. The axes are scaled such that 50 units  =  one grid spacing. The results show a field radius of 1.0 (top right), 1.1 (bottom left) and 1.2 (bottom right).</p

Example mapping. An to mapping with many-to-one structure.

<p>Example mapping. An to mapping with many-to-one structure.</p

Link count versus error.

<p>Combined mean overlap and field counts required to provide an expected deviation of 1 percent of the map's area. This approximates the number of links between maps of similar density.</p

Sigmoid performance.

<p>Error plot for a range of Sigmoid encoders using vector average decoding tested over a range of radii.</p

Partial population.

<p>Fields being generated from a structured polar grid.</p

Transformation information loss.

<p>A reverse transform using the robot distortion space, i.e. from the points in hand space (left) to eye space (right). The ideal result would be a regular grid of points. The errors in the bottom rows of the square grid are caused by the distortion squeezing points into the polar centre in the bottom left corner.</p