---
OA_type: closed access
_id: '2423'
abstract:
- lang: eng
  text: A finite set N ⊃ Rd is a weak ε-net for an n-point set X ⊃ Rd (with respect
    to convex sets) if N intersects every convex set K with |K ∩ X| ≥ εn. We give
    an alternative, and arguably simpler, proof of the fact, first shown by Chazelle
    et al. [7], that every point set X in Rd admits a weak ε-net of cardinality O(ε-d
    polylog(1/ε)). Moreover, for a number of special point sets (e.g., for points
    on the moment curve), our method gives substantially better bounds. The construction
    yields an algorithm to construct such weak ε-nets in time O(n ln(1/ε)). We also
    prove, by a different method, a near-linear upper bound for points uniformly distributed
    on the (d - 1)-dimensional sphere.
article_processing_charge: No
author:
- first_name: Jiří
  full_name: Matoušek, Jiří
  last_name: Matoušek
- first_name: Uli
  full_name: Wagner, Uli
  id: 36690CA2-F248-11E8-B48F-1D18A9856A87
  last_name: Wagner
  orcid: 0000-0002-1494-0568
citation:
  ama: 'Matoušek J, Wagner U. New constructions of weak epsilon-nets. In: <i>Proceedings
    of the Nineteenth Annual Symposium on Computational Geometry</i>. Association
    for Computing Machinery; 2003:129-135. doi:<a href="https://doi.org/10.1145/777792.777813">10.1145/777792.777813</a>'
  apa: 'Matoušek, J., &#38; Wagner, U. (2003). New constructions of weak epsilon-nets.
    In <i>Proceedings of the nineteenth annual symposium on Computational geometry</i>
    (pp. 129–135). San Diego, CA, United States: Association for Computing Machinery.
    <a href="https://doi.org/10.1145/777792.777813">https://doi.org/10.1145/777792.777813</a>'
  chicago: Matoušek, Jiří, and Uli Wagner. “New Constructions of Weak Epsilon-Nets.”
    In <i>Proceedings of the Nineteenth Annual Symposium on Computational Geometry</i>,
    129–35. Association for Computing Machinery, 2003. <a href="https://doi.org/10.1145/777792.777813">https://doi.org/10.1145/777792.777813</a>.
  ieee: J. Matoušek and U. Wagner, “New constructions of weak epsilon-nets,” in <i>Proceedings
    of the nineteenth annual symposium on Computational geometry</i>, San Diego, CA,
    United States, 2003, pp. 129–135.
  ista: 'Matoušek J, Wagner U. 2003. New constructions of weak epsilon-nets. Proceedings
    of the nineteenth annual symposium on Computational geometry. SoCG: Symposium
    on Computational Geometry, 129–135.'
  mla: Matoušek, Jiří, and Uli Wagner. “New Constructions of Weak Epsilon-Nets.” <i>Proceedings
    of the Nineteenth Annual Symposium on Computational Geometry</i>, Association
    for Computing Machinery, 2003, pp. 129–35, doi:<a href="https://doi.org/10.1145/777792.777813">10.1145/777792.777813</a>.
  short: J. Matoušek, U. Wagner, in:, Proceedings of the Nineteenth Annual Symposium
    on Computational Geometry, Association for Computing Machinery, 2003, pp. 129–135.
conference:
  end_date: 2003-06-10
  location: San Diego, CA, United States
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2003-06-08
date_created: 2018-12-11T11:57:34Z
date_published: 2003-06-08T00:00:00Z
date_updated: 2026-05-28T08:11:49Z
day: '08'
doi: 10.1145/777792.777813
extern: '1'
fulldoi: https://doi.org/10.1145/777792.777813
language:
- iso: eng
month: '06'
oa_version: None
page: 129 - 135
publication: Proceedings of the nineteenth annual symposium on Computational geometry
publication_identifier:
  isbn:
  - '9781581136630'
publication_status: published
publisher: Association for Computing Machinery
publist_id: '4502'
quality_controlled: '1'
status: public
title: New constructions of weak epsilon-nets
type: conference
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2003'
...
---
OA_place: publisher
OA_type: free access
_id: '3556'
abstract:
- lang: eng
  text: We define the Morse-Smale complex of a Morse function over a 3-manifold as
    the overlay of the descending and as- cending manifolds of all critical points.
    In the generic case, its 3-dimensional cells are shaped like crystals and are
    sepa- rated by quadrangular faces. In this paper, we give a combi- natorial algorithm
    for constructing such complexes for piece- wise linear data.
article_processing_charge: No
author:
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
- first_name: John
  full_name: Harer, John
  last_name: Harer
- first_name: Vijay
  full_name: Natarajan, Vijay
  last_name: Natarajan
- first_name: Valerio
  full_name: Pascucci, Valerio
  last_name: Pascucci
citation:
  ama: 'Edelsbrunner H, Harer J, Natarajan V, Pascucci V. Morse-Smale complexes for
    piecewise linear 3-manifolds. In: <i>Proceedings of the Nineteenth Annual Symposium
    in Computional Geometry</i>. Association for Computing Machinery; 2003:361-370.
    doi:<a href="https://doi.org/10.1145/777792.777846">10.1145/777792.777846</a>'
  apa: 'Edelsbrunner, H., Harer, J., Natarajan, V., &#38; Pascucci, V. (2003). Morse-Smale
    complexes for piecewise linear 3-manifolds. In <i>Proceedings of the nineteenth
    annual symposium in Computional geometry</i> (pp. 361–370). San Diego, CA, United
    States: Association for Computing Machinery. <a href="https://doi.org/10.1145/777792.777846">https://doi.org/10.1145/777792.777846</a>'
  chicago: Edelsbrunner, Herbert, John Harer, Vijay Natarajan, and Valerio Pascucci.
    “Morse-Smale Complexes for Piecewise Linear 3-Manifolds.” In <i>Proceedings of
    the Nineteenth Annual Symposium in Computional Geometry</i>, 361–70. Association
    for Computing Machinery, 2003. <a href="https://doi.org/10.1145/777792.777846">https://doi.org/10.1145/777792.777846</a>.
  ieee: H. Edelsbrunner, J. Harer, V. Natarajan, and V. Pascucci, “Morse-Smale complexes
    for piecewise linear 3-manifolds,” in <i>Proceedings of the nineteenth annual
    symposium in Computional geometry</i>, San Diego, CA, United States, 2003, pp.
    361–370.
  ista: 'Edelsbrunner H, Harer J, Natarajan V, Pascucci V. 2003. Morse-Smale complexes
    for piecewise linear 3-manifolds. Proceedings of the nineteenth annual symposium
    in Computional geometry. SCG: Symposium on Computational Geometry, 361–370.'
  mla: Edelsbrunner, Herbert, et al. “Morse-Smale Complexes for Piecewise Linear 3-Manifolds.”
    <i>Proceedings of the Nineteenth Annual Symposium in Computional Geometry</i>,
    Association for Computing Machinery, 2003, pp. 361–70, doi:<a href="https://doi.org/10.1145/777792.777846">10.1145/777792.777846</a>.
  short: H. Edelsbrunner, J. Harer, V. Natarajan, V. Pascucci, in:, Proceedings of
    the Nineteenth Annual Symposium in Computional Geometry, Association for Computing
    Machinery, 2003, pp. 361–370.
conference:
  end_date: 2003-10-26
  location: San Diego, CA, United States
  name: 'SCG: Symposium on Computational Geometry'
  start_date: 2003-08-06
date_created: 2018-12-11T12:03:57Z
date_published: 2003-06-08T00:00:00Z
date_updated: 2026-05-20T14:15:30Z
day: '08'
doi: 10.1145/777792.777846
extern: '1'
fulldoi: https://doi.org/10.1145/777792.777846
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1145/777792.777846
month: '06'
oa: 1
oa_version: Accepted Version
page: 361 - 370
publication: Proceedings of the nineteenth annual symposium in Computional geometry
publication_identifier:
  isbn:
  - '9781581136630'
publication_status: published
publisher: Association for Computing Machinery
publist_id: '2829'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Morse-Smale complexes for piecewise linear 3-manifolds
type: conference
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2003'
...
