This ASCII format is a very simple one. It consists in a list of all the critical points with some useful information for each of them.

#critical points | Header |
---|---|

#X0 X1 X2 value type pair_id boundary | Header identifying each column |

#NDIMS NPOINTS | Number of dimensions and number of points |

X0 X1 X2 value type pair_id boundary | The value of the fields for the first point |

.... | One such line for each NPOINTS points |

Notations:

- -
**X_0**,...,**X_ndims**: the coordinates of the pooint - -
**value**: Value of the field. - -
**type**: the critical index of the point. A value of NDIMS+1 indicates a bifurcation point or a trimmed extremity. - -
**pair_id**: index of the other critical point in the persistence pair. C style convention is used, indices starting at 0, and points without perisstence pairs have their own index for*pair_id*. - -
**boundary**: value can be*0*,*1*or*2*when the point is inside the domain, on the boundary, or outside (e.g. at infinity)