# algorithm Matlab function 'stream2' and 'stream3' use to compute streamline

Can anyone explain how the MATLAB functions: stream2(x,y,z,u,v,startx,starty) and stream3(x,y,z,u,v,startx,starty) compute stream lines from vector data u and v? In the stream2.m file, it calls the stream3c function. I assume it is a .c file but unable to see it. Thanks in advance.

• In older MATLAB versions (R13, R14 or so) you could find the sources in the folder $MATLABPATH/toolbox/matlab/specgraph/private/src/. I just checked, but the src directory is gone in my 2013b installation. You can try to find that file to find out the underlying algorithm. I however suspect that it is an integration method which you can find in standard textbooks. Perhaps someone can recommend a reference here. – Christian Waluga Aug 1 '14 at 11:24 • Cross-post: stackoverflow.com/questions/25006973/… – Christian Clason Aug 1 '14 at 12:13 • From the code linked there, it looks like a simple explicit Euler integration of the ODE$(\dot x,\dot y)(t) = (u(x,y),v(x,y))$for a given set of starting points$(x,y)(0)\$. – Christian Clason Aug 1 '14 at 12:18