is an array of arrays awkward or desirable programming practice?

I have undertaken a project to write a UDF that will take a parametric array as an argument. The thing that is looking awkward to me is that each element of the parametric array will be an array/range itself. Recognizing that a series of polynomials is an imperfect example, here is how it looks for a series of polynomials.

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I'm sure I could process polys() into a 2D array before moving on to the main processing loops, but is such a step necessary? Do I just need to bite the bullet and become more comfortable with this "array of arrays" notation? Or do "real" programmers prefer not to work with this array of arrays structure?
Does anything change if I add that in my real project, each element of polys is a 2D range? Which is really worse:
a 3D array polys(i,j,k)
a paramarray of 2D arrays polys(i)(j,k)

I realize that this kind of thing may not have a solid answer, but I would appreciate some feedback from more experienced programmers.

As you suggest, it depends. Jagged arrays can be quite useful (ie each Sub array may not have the same dimensions). Even when the sub arrays are the same size it can be handy to have an array of arrays - especially if you plan to reorder the first dimension.

Mostly I'd say if your function is going to receive an array of arrays, you may as well process that way rather than going to the trouble of converting to one n-dimensional array.

Hope that's of some use.

Thanks for the responses.

An Additional comment. While my example is hard coded for 4 polys, the real function would have anywhere from 1 to 7 or so polys. The advantage of using a parametric array is that I do not need a list of 7 optional arguments for each poly. I can have the one parametric array argument, and the number of ranges included in that parametric array tells the function how many polys are being calculated. Perhaps this expresses the question differently, when working with arrays/ranges, is it preferable to use a list of optional arguments or a parametric array?

Perhaps the other idea, brought on by this "jagged array" concept, is that sometimes each poly will be a different order (so to speak). So poly 1 may be a cubic, like shown, but poly 2 is a quartic, and poly 3 is linear, and poly 4 is a single constant, or whatever. This could add extra advantage to the use of a jagged array.

It looks like this "array of arrays" is a useful concept that other programmers use, so I guess I will bite the bullet and make myself comfortable using it.

Hi Shorty,

Originally Posted by MrShorty

........
It looks like this "array of arrays" is a useful concept that other programmers use,....

_ I have always been a great fan of Arrays, keeping as much “ away from the spreadsheet “ , capturing and pasting to the spreadsheet in “One Liners” etc.
_ I sort of fell into thinking in the two dimensional “row” , “column” way of thinking about them.
_ But then I hit on the further possibilities in a few Threads..
http://www.mrexcel.com/forum/excel-q...d-array-2.html
of, in particular the idea of a 1D Array of 2D Arrays. I have found that took my efficiency of Arrays that one step further, especially when sorting stuff from multiple sheets,
_ every element in the “ Outer” 1 D Array is a sheet , and the “grid” of a sheet is each of the “Inner” 2 D Arrays.
_ A simple and obvious concept, but it seems to really “fit” well sometimes..

Originally Posted by MrShorty

........... so I guess I will bite the bullet and make myself comfortable using it.

_ I always have a second Monitor with a big Watch window open in with all my Important Arrays in it when I develop Codes using Arrays
http://www.mrexcel.com/forum/lounge-...aneously.html?
_ I am not sure If i could live without that, yet..
Alan

Doc.AElstein: Your example of a 1D array of "sheets", where each "sheet" has a 2D array is a pretty good parallel to what I see happening in this calculation. Rather than "sheets", I see "blocks" of cells on the same sheet. In many ways, I would have defaulted to a 3D array, except the parametric array creates an array of "range" objects. Now that I can see that others use this kind of data structure to good effect, I will try to learn and use it as well.

Hi

Originally Posted by MrShorty

.. Now that I can see that others use this kind of data structure to good effect, I will try to learn and use it as well.

-- and i see you use XP. I use mostly XP and Vista, and mostly XL2007. I swear by the 2 Monitor bit - That works very well in those Operating systems. I use a Big Old Telly as the second Monitor. I strongly recommend that to get a big Watch Window to look inside your Arrays as they are being filled. ( As well of course of being able to get both the spreadsheet and the VB Development Window clearly visible at the same time. Although as i capture in and paste out in one go typically, i rarely need to look at the spreadsheet )
Alan

wrong screen