Array

Old Timer

New to Spin. I haven't been able to find any mention of this. Does spin provide for multi dimension arrays or lists? For example, how can I set up an indexed·list or array of x/y coordinates in Spin without using a string· or concatanated series of integers, which would then need to be parsed?

Thanks,

BobA

Paul Baker

There is no direct support multi-dimensional arrays, though data[noparse][[/noparse]x + y * DIMX] works just fine. (DIMX is a constant equal to the number of elements in the X direction).

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

Old Timer

Thanks for the quick reply Paul. I don't understand what·you mean with that equation as it applies to my question. Unless I'm missing your point, if I want to set up an indexed·list of "stops" using a grid and coordinates that describe a path for a robot to traverse with one dimentional arrays, I either need to parse·elements·or use multiple synchronized arrays (which is less than ideal). What am I not seeing?

Thanks again,



BobA

Mike Green

What you're not seeing is that Paul was describing how multidimensional arrays are actually implemented in most languages. Memory is only one dimensional. If you have a 4 x 5 array, the compiler will group 4 elements for the X subscripts for a given Y subscript value and repeat that 5 times. In calculating the location in memory, you have to multiply the Y value by the dimension of X (4 in this case) to get X + Y * DimX which is the offset in memory of the array element. Obviously, if the dimensions start at anything other than zero, you have to adjust X and Y appropriately.

Old Timer

AHA! Thank you, Mike,