' - - File: VII_Slope1.txt

' This program and VIISlope2 to follow shows the difference between the displays:
'     This program only derives the particular solutions FROM the initial values forward
'     as an implied direction--the slope show a direction. For example, if one of the two
'     variables represented time.

'     The VIISlope2 program (under user option) plots both directions from the initial
'      values. No direction is implied and the arrows are removed. Note the differences
'      between the two plots.

F{x,y} = -2 * x * y                  ' The slope function.

a = -2  :  b = 2  :  n = 15
c = -2  :  d = 2  :  m = 15

x1 = - 0.75  :  y1 = -1          ' Initial condition for a particular solution.
x2 = -0.75   :  y2 = 1           ' A second for another particular solution.

PlotSlopeField[F, {a,b,n}{c,d,m}{x1,y1}{x2,y2}]

' Use the Shift-Z to zoom inward.  Note the arrows for the assumed directed flow.

