Some years ago I put together a collection of Matlab files for plotting direction fields and numerically generated solutions of systems of ODEs in 1, 2, and 3 dimensions.  I have used it for teaching both undergraduate and graduate courses. Along with the *.m and *.mat files you will find Instructions.pdf which explains features and use of the commands.  Note that it has been some years since I last updated these.  It is possible that some features of Matlab have changed, which would require modification.

Link to the files.