Practical Use for 4D+ Arrays [duplicate]

Question

I have been studying Java and C++ this year, and I am wondering; what practical uses are there for a 4 or even 5 dimensional array? My teacher basically says that you are using the wrong datatype if you want to use a 4 dimensional array.

Have you ever used a 4 of 5 (or more) dimensional array? What did you use it for? What practical uses can you think of for them?

Thanks!

Answer 1

A practical use of a 4D array is to keep track of a 3d object, could keep track of [x-cord][y-cord][z-cord][time]. This 4D array would be a useful use of a 4D array. This could keep track of a range of cords and time, and the value in the array could say the speed of of the object.

Speed = arr[5][9][6][1500];

That would record the speed of the object when it was at x cord 5, y cord 9, z cord 6, and say been alive for 1500 seconds.

As for your 5D array:

int left; //#of cars left in world
left = allCars[year][brand][color][condition][horsepower];

brand count be an int(have a table of values aka Ferrari = 1, same with color. Condition could be on a scale of 0 being destroyed, to 1 being brand new).

Then you could find the # of 1947 Ferrari's that are red in brand new condition with 200 horsepower.

Aka in general you could use many dimensional arrays to keep track of large databases of things.

Answer 2

You may create a Sodoku hypercube with 4 dimensions and then you can store the number which the user enters into a 4dimensional int array.

Rotating 4D hypercube (GIF movie). Imagine a person who lives in 4 spatial dimensions, watching a hypercube rotate. The 4-dimensional person has a 3-dimensional retina in each of its 2 eyes (two eyes suffice for depth perception, even in 4D). Each retina records a 3-dimensional image.

This image shows what the 4-dimensional person sees, with the extra dimension shown as a variation in colour. That is, the horizontal, vertical, and `colour' directions correspond to the 3 directions on the 3-dimensional retina of the 4-dimensional person. The vertical bar to the right of the picture shows the correspondence between colour and position in the extra dimension.

Also you may check the Tesseract