Hi, I am trying to solve a first order differential equation numerically using dsolve. The equation is of the form dx/dt = k1 x + k2 |x|^2 x where x(t) is a complex valued function and k1 and k2 are complex constants. I get the following warning/error from maple10 Warning, abs is not differentiable at non-real arguments For this equation dsolve only gives me the solution for relatively short times (t ~1 or 2) and I know there is a solution valid at large times >>1. Obviously I could cast this equation into a system of 2: one for the real part and the other for the imaginary part.

I would like to read a data file that is located in "My Documents" folder using the open command, but maple cannot find the file. The file name is data1.txt and I think the complete folder name is c:\Documents and Settings\dhalpern\My Documents I have tried INP := fopen("C:\Documents and Settings\dhalpern\My Documents\data1.txt",READ,TEXT); but I get the following error message. Error, (in fopen) file or directory does not exist I have checked that the file and directory DO exist. If I place the data file in c:\ then I don't have any problems but I would prefer to have my files in My Documents.