
  ttrraaccee -- ccrreeaatteess,, ddeelleetteess,, oorr mmaanniippuullaatteess ttrraacceess wwiitthhiinn aa ggrraapphh

  UUSSAAGGEE

        trace create <graph> [<object>] | list <graph> | [delete | store |
            clear] <graph> <trace-list>

  DDEESSCCRRIIPPTTIIOONN

  A trace is essentially a single series, or chain of points, within a graph.
  This command performs several different operations on the traces within a
  single graph. They are as follows:

  "trace create <graph> [<object>]" creates a new trace and returns its name,
  which is an integer index into the graph's trace() array. graph is the
  integer name of the graph that was returned when the graph was created and
  is displayed in the graph's title bar. If no object is specified, the new
  trace will not have one. If an object is specified, it can be either the
  path to a real-valued object to be graphed, such as output(3).unit
  (2).output, or it can be a Tcl function that returns a real value.

  "trace list <graph>" returns a list of the numbers of all of the traces
  within the graph.

  "trace delete <graph> <trace-list>" destroys all of the traces within the
  graph whose numbers are listed. * refers to all of the traces in the graph.

  "trace store <graph> <trace-list>" stores the given traces. When a trace is
  stored, an inactive, transient copy of it is created (in a new color) and
  the original trace is cleared.

  "trace clear <graph> <trace-list>" clears the given traces. When a trace is
  cleared, all of the points are removed from the trace. But, otherwise, the
  trace remains the same.

  You can read more about graphs and traces in the _G_r_a_p_h_s_ _s_e_c_t_i_o_n of the main
  manual.

  EEXXAAMMPPLLEESS

  To create a graph, add a trace to it, and change the trace's color to red,
  do:

        lens> set g [graph create]
        lens> set t [trace create $g error]
        lens> setObject graph($g).trace($t).color red
        lens> graph refresh $g

  SSEEEE AALLSSOO

  _g_r_a_p_h_O_b_j_e_c_t, _g_r_a_p_h, _e_x_p_o_r_t_G_r_a_p_h

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    Last modified: Wed Nov 15 10:52:38 EST 2000

