Talk:MATLAB Programming/Advanced Topics/Toolboxes and Extensions/Symbolic Toolbox

The most important thing about the symbolic math toolbox is that (as far as I can tell), unlike MATLAB, Maple is a symbolic kernel, not a numeric one. So, for example, you can manipulate fractions exactly by storing them as symbolic variables, rather than dealing with roundoff errors... I also use it to determine expressions for functions that would be a pain in the butt to find by hand, and then just copy them and paste into the program I want to use them in. Maple also lets you use variable-precision arithmetic, not sure how accurate or useful that is but it is there.

The downside is that it often will give you really complicated stuff that you can't really do much with. I haven't figured out how to make it output indecies, which means I manually have to go in and put them in after the toolbox is done running. Mattb112885 15:26, 19 August 2006 (UTC)


 * I have added prettymuch everything I know about the toolbox, I'm not sure how to use the linear algebra or VPA stuff so if someone knows better than me please add it! Mattb112885 23:08, 8 September 2006 (UTC)

What is intended by the "syms a(1)" command at the end of the Symbolic Variables? I don't think that should be there since it doesn't make sense (or at least I can't figure out what you mean). Are the parens for indexing or function evaluation? (edit: aha from later examples I think you mean for parens to be indexing). Also the example that results in "a=[a a2]" looks confusing since I can't imagine why people would want to have the MATLAB variable "a" represent "[a a2]" - it's too confusing.

Also later on in the Symbolic Function section you can see how sym('a(1)') and sym('a(2)') is not useful. Just stick with "syms a" or perhaps if you really want to say that a is a 2 element symbolic variable then "syms a1 a2" and "a = [a1 a2];".

Also for the section about solving and symbolic functions the example confuses assignment = with equality ==. I recommend adding a discussion about what = means.


 * Thank you for your comments. I agree, it is kind of unnecessary to use that kind of syntax, I removed it in favor of just the array. The second point, yeah that was weird, I don't know why I did that.. the third, equality is addressed in the "logic" section but don't think assignment is addressed anywhere, so that's something to do later, any suggestions where to put it? And where did I mistake assignment with equality, or did you fix that already? Mattb112885 05:22, 29 November 2006 (UTC)

"There is no function to directly change a symbolic variable into a function handle, unfortunately." - I they have added one recently: matlabFunction. Sheepe2004 (discuss • contribs) 12:34, 29 July 2011 (UTC)