This is documentation for Mathematica 7, which was
based on an earlier version of the Wolfram Language.

# StreamScale

 StreamScale is an option to StreamPlot, ListStreamPlot, and related functions that determines the length and arrowhead size of streamlines that are drawn.
• StreamPlot and related functions effectively find streamlines by following the flow of the vector field. StreamScale determines how the streamlines found should be segmented for display.
• Each streamline segment is rendered as an Arrow, with its own arrowhead.
 Automatic automatically determine streamline scale None draw no arrows for streamlines Full use full streamlines without segmentation {seg,npts,aratio,sfun} use explicit specification of streamline scaling
• The setting StreamScale->{seg, npts, aratio, sfun} allows explicit specification of how streamlines should be broken into segments, and how each segment should be scaled.
• The parameter seg is analogous to a Dashing specification for segments of a streamline. The following forms can be used:
 s equivalent to {s, s/15} {s1,s2,...} successive line segments of length s1, s2, ... with every other segment rendered and repeated cyclically Large,Medium,Small,Tiny use large, medium etc. segment lengths
• The following settings can be used for npts to control the number of points rendered on each streamline segment:
 2 use two points, giving a straight streamline segment n use up to n points for each streamline segment All use all computed points for each streamline segment Automatic use an automatic method based on curve simplification
• Every streamline segment effectively lies in a curved strip, with the arrowhead for the segment spanning one end of the strip.
• The following settings can be used for aratio to control the aspect ratio of the streamline strip:
 r absolute aspect ratio relative to the longest line segment Scaled[r] relative aspect ratio relative to each line segment Automatic automatic method based on the number points
• After the length of segments is determined by seg, they can be rescaled by applying the function sfun. The following settings can be used:
 None do no rescaling func a function of x, y, vx, vy, Norm[{vx, vy}] Automatic automatically determine rescaling
Specify the length of streamline segments to use:
Specify the number of points used per segment:
Specify the size of the arrows used:
Specify the length of streamline segments to use:
 Out[1]=

Specify the number of points used per segment:
 Out[1]=

Specify the size of the arrows used:
 Out[1]=
 Out[2]=
 Scope   (3)
Use curves for the streamlines:
Use a single segment for each streamline: