dfield6

代码说明：

  DFIELD6 is an interactive tool for studying single first order differential equations. When DFIELD6 is executed, a DFIELD6 Setup window is opened. The user may enter the differential equation and specify a display window using the interactive controls in the Setup window. When the Proceed button is pressed on the Setup window, the DF Display window is opened. At first this window displays a direction line field for the differential equation. When the mouse button is depressed in the DFIELD6 Display window, the solution to the differential equation with that initial condition is calculated and plotted. Oher options are available in the Options menu. These are fairly self explanatory. The Settings option allows the user to change several parameters. Included here are the possibilities of using a vector field instead of the default line field, and of changing the number of field points computed and displayed.