Exports the 1-skeleton to a graph using the igraph library.

vertex_scale | scaling function for the vertex sizes. |
---|---|

vertex_min | minimum vertex size. |

vertex_min | maximum vertex size. |

col_pal | color palette to color the vertices by. |

an igraph object.

This method converts the 1-skeleton of the Mapper to an igraph object, and assigns some
default visual properties. Namely, the vertex attributes "color", "size", and "label" and the
edge attribute "color" are assigned.
The vertex colors are colored according on the given color palette (default is rainbow) according
to their mean filter value (see `bin_color`

). The vertex sizes are scaled according
to the number of points they contain, scaled by `vertex_scale`

, and bounded between
(`vertex_min`

, `vertex_max`

). The vertex labels are in the format "<id>:<size>".

The edges are colored similarly by the average filter value of the points intersecting
both nodes they connect too.