Spin Arrays

mynet43

Is there a way to declare a two dimensional array in SPIN?

I want to do some matrix arithmetic and this would make it easier.

I couldn't find anything in the manual.

The obvious: long phi doesn't seem to work.

Is there a way to do this or do I have to declare it single dimensioned and then play with the index?

Thanks for your help.

Jim

Bergamot

There's no reason that I can see why you couldn't make an array of arrays, i.e. an array filled with pointers to other arrays.

The indexing method is more time/space efficient though, at the cost of code complexity.

deSilva

The word "array" in SPIN is a misnomer, there are no arrays but vectors of memory cells only. So you have to reinvent one of the well-known three kinds of array implementations, as every assembly language programmer:
- brute force multiplication pos = x*ysize +y (or y*xsize+x - you have the choice)
- intermediate addressvector (preset: arr[noparse][[/noparse]x]:= @arrspace*x*ysize
- sparse matrices using bitvectors, well above this thread I guess...

Alas, there is no such thing as this practical denotation "arr[noparse]/noparse]x][noparse][[/noparse]y]", you have to use something like LONG[noparse][[/noparse]arr[noparse][[/noparse]x[noparse][[/noparse]y]

And don't get confused with longs, words, or bytes...
Note that the LONG I use has nothing to do with the sizing of the "arr" address vector (which could be WORDs as well), but with the size of your element in "arrspace"

mynet43

Thanks for the quick answers. That's what I was afraid of.

I know how to do it, it's just a little trickier to debug.

Jim