
  ccoonnnneeccttGGrroouuppss -- ccrreeaatteess lliinnkkss wwiitthh aa ssppeecciiffiieedd ppaatttteerrnn bbeettwweeeenn ggrroouuppss

  UUSSAAGGEE

        connectGroups <group-list1> (<group-list>)* [-projection <proj-type>
    |
            -strength <strength> | -mean <mean> | -range <range> |
            -type <link-type> | -bidirectional]

  DDEESSCCRRIIPPTTIIOONN

  This command creates sets of links between groups. Each group in group-
  list1 will project to each group in the second group list. Those in the
  second list will project to those in the third and so on. By default this
  creates a full projection, but several patterns of sparse projections may
  also be specified.

  Possible projection types (or connectivity patterns) are FULL, UNLESIONED,
  RANDOM, FIXED_IN, FIXED_OUT, FAIR, FAN, and ONE_TO_ONE. These may be
  abbreviated by any unique prefix. For sparse patterns, the strength is a
  floating point number in the range [0,1] specifying the density of the
  connectivity, as described below. It must be specified for all of the
  sparse patterns, but not for FULL or ONE_TO_ONE.

  In describing the projection types, S is the specified connectivity
  strength, I is the number of units in the sending group, O is the number of
  units in the receiving group and f() is the floor function.

  FULL creates the dense projection from each sending unit to all receiving
  units. This is the default.

  UNLESIONED is like FULL but only creates connections between healthy,
  unlesioned units in the two groups. This can be used to create a partial
  projection.

  RANDOM simply connects each pair of pre- and post-synaptic cells with
  probability S.

  FIXED_IN ensures that each postsynaptic unit receives exactly f(S*I)
  inputs. The number of outputs from a given presynaptic unit may vary.

  FIXED_OUT ensures that each presynaptic unit has exactly f(S*O) outputs.

  FAIR ensures that each sending unit will have exactly f(S*O) outputs and
  each receiving unit will have either floor or ceiling of (I*f(S*O) / O)
  inputs.

  FAN causes each input unit to project to the f(S*O) outputs that are
  closest to it. The closeness measure wraps around the ends of the arrays.

  ONE_TO_ONE connects each unit in the sending group to the corresponding
  unit in the receiving group. The two groups need not have the same number
  of units; one link will be formed for each unit in the smaller of the two
  groups. For one-to-one connections, the mean defaults to 1.0 and the range
  defaults to 0.0. The weights are frozen by default.

  If range or both mean and range are given, they will determine the
  parameters used for randomizing weights in this projection. If left
  unspecified, the network defaults will be used for these links.

  By default the links in the new projection will have a type with the same
  name as the sending group. This can be overridden by specifying a different
  link type.

  The -bidirectional flag will cause a projection to be formed in the reverse
  direction whenever one is formed in the forward direction.

  EEXXAAMMPPLLEESS

  To create a full projection (of type "input") from group "input" to group
  "hidden" which uses range -1.0+/-0.5 when randomizing weights in this
  projection:

        lens> connectGroups input hidden -mean -1.0 -range 0.5

  To create bidirectional FAIR projections between groups "in" and "hid1",
  "in" and "hid2", "hid1" and "out", and "hid2" and "out" with approximately
  50% of the possible connections and with each link having type "t1":

        lens> connectGroups in {hid1 hid2} out -bi -p FAIR -s 0.5 -type t1

  SSEEEE AALLSSOO

  _a_d_d_G_r_o_u_p, _c_o_n_n_e_c_t_G_r_o_u_p_T_o_U_n_i_t_s, _c_o_n_n_e_c_t_U_n_i_t_s, _e_l_m_a_n_C_o_n_n_e_c_t, _a_d_d_L_i_n_k_T_y_p_e,
  _d_i_s_c_o_n_n_e_c_t_G_r_o_u_p_s, _s_e_t_L_i_n_k_V_a_l_u_e_s

  ---------------------------------------------------------------------------
    Last modified: Wed Nov 15 11:12:30 EST 2000

