On Saturday, March 31, 2012 10:40:24 PM UTC+5:30, Stefan Krastanov wrote: > > > I think most of the explicit equations can be handled by your > > implementation. > > I don't think the implicit equations involving such expressions can be > > plotted > > even in mathematica / Matlab.( haven't verified it though). Plotting > using > > interpolation is possible, but it might lead to erroneous plots and hence > > it is better not to implement a interpolating plots for such functions. > > Matlab can not (matlab is not good for anything symbolic or implicit > anyway) but Mathematica definitely can plot such expressions. > > Why is interpolating a problem? All that you need to know is that your > function is monotone on the interval on which you are working, thus > just calculating one or two points inside your interval should be a > good guess. > The initial block is going to be huge. The block is recursively subdivided and evaluated. If I have a false positive on one of the big blocks, the plot will be outright wrong. One thing we can do is to break down the whole region into a grid and assume that the function is monotonic in each cell and evaluate the expression. I think this will be the best solution to such functions.
> Of course there will be pathological cases, but better > fail only on patological cases than fail on every single expression > that is more complicated than a combination of sin, sqrt and abs. > > Again, maybe I am missing something, but for the moment I do not see what > it is. > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To view this discussion on the web visit https://groups.google.com/d/msg/sympy/-/_u5OQ8dBEaEJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
