Program help needed

[DrD]

(11-22-2014 01:44 PM)Han Wrote:  [quote='DrD' pid='21758' dateline='1416663364']
1. Can the above program be constructed to return the {x,y} result? --> [-3*y^3+2*x,-9*x*y^2]

Use mat2list(). It will give you a list of components with comma separators (but it won't be a vector in the normal sense).

Sorry, Han, I was asking: (in terms of the list variables), "how can I get the program (top post) to produce the same result as grad(x^2-3*x*y^3,{x,y}); does when it's manually entered in the CAS view entry line?" grad(x^2-3*x*y^3,{x,y}); --> [-3*y^3+2*x,-9*x*y^2]

Specifically, the program line: return grad(x^2-3*x*y^3,{x,y}); crashes at run-time due to it's variables being auto-initialized to 0. (It's a CAS command vs. non-CAS program thing.)

Thanks for your help!

AND thanks also, to Joe for pointing out that unchecking the "Textbook Display" on pg 2 of Home settings, FIXES the lack of "comma separation in the vector" problem! Otherwise the result of the above example would display like: [-3*y^3+2*x -9*x*y^2] and that's just not good!

-Dale-