`slopefield`

To draw a slope field for the differential equation dy/dx=f(x,y) (or dy/dx=f(x)), use:

picture slopefield(real f(real,real), pair a, pair b, int nx=nmesh, int ny=nx, real tickfactor=0.5, pen p=currentpen, arrowbar arrow=None);Here, the points

`a`

and `b`

are the lower left and upper
right corners of the rectangle in which the slope field is to be drawn,
`nx`

and `ny`

are the respective number of ticks in the
x and y directions, `tickfactor`

is the fraction of
the minimum cell dimension to use for drawing ticks, and `p`

is
the pen to use for drawing the slope fields.
The return value is a picture that can be added to
`currentpicture`

via the `add(picture)`

command.
path curve(pair c, real f(real,real), pair a, pair b);takes a point (

`c`

) and a slope field-defining function `f`

and returns, as a path, the curve passing through that point. The points
`a`

and `b`

represent the rectangular boundaries over which
the curve is interpolated.
Both `slopefield`

and `curve`

alternatively accept a function
`real f(real)`

that depends on x only, as seen in this example:

import slopefield; size(200); real func(real x) {return 2x;} add(slopefield(func,(-3,-3),(3,3),20,Arrow)); draw(curve((0,0),func,(-3,-3),(3,3)),red);