Simple Mapping

Currently there are a lot of instances that we need to map data from the user interfaces or user interfaces to data.

premise #1: That greater number is divisible by the lower number.

#X = number of X elements

#Y = number of Y elements

Xr = X ratio against Y

Yr = Y ratio against X

R = range of single element of greater size

M = map

 

if #X == #Y, mapping is 1:1

if #X > #Y, mapping is Xr:Yr, where Xr > Yr

if #X < #Y, mapping is Xr:Yr, where Xr < Yr

Constant R is:

        X/Y, where X > Y or

        Y/X, where X < Y

Mapping from X -> Y, where X > Y:

        X/R = q,    if q has zero remainder then M is q or

                If q has a remainder then M is q+ 1

                until X=1

Mapping from X -> Y, where X < Y:

X*R = p,    M is p - (R-1)

Example 1:

    If X=20, Y=5

    R = 20/5 = 4

    M, X->Y :

20/4=5     = q , then 20 -> 5

19/4=4.? = q+1, then 19->5

18/4=4.? = q+1, then 18->5

17/4=4.? = q+1, then 17->5

    So, 20,19,18,17 ->5

16/4=4 = q, then 16->4

15/4=3 = q+1, then 15->4

14/4=3.? = q+1, then 14->4

…

7/4=1.? = q+1, then 7->2

…

4/4=1 = q, then 4->1

¾= 0 = q+1, then 3->1

2/4 =0 = q+1, then 2->1

¼=0 = q+1, then 1->1

 

    So, 4,3,2,1 -> 1

 

Example 2:

    If X=3, Y=15

    R = 15/3 = 5

    X*R = 3*5=15

        15-(R-1) = 15-(5-1)=11

        15-(4-1-1) = 15-(4-1)=12

        15-(3-1) = 15-(3-1) = 13

        …

        15-(1-1) = 15-(1-1)=15

    So, 3 -> 11,12,13,14,15

    If X=1,

    X*R = 1*5=5

        5-(5-1)=1

        5-(4-1)=2

        5-(3-1)=3

        5-(2-1)=4

        5-(1-1)=5

    So, 1 -> 1,2,3,4,5

Sample Code:

Int main()
{

UINT x=300,y=5;

        CMapping mapper;

        mapper.StartMap(x,y);

        mapper.DisplayMapToTerminal();

 

        CArray<UINT,UINT> map;

        mapper.FindMap(3,map);

        mapper.DisplayFindMap(map);

 

        UINT z=0;

        mapper.FindMap(108,z);

        cout << "\n" << z << "\n";

        system("PAUSE");

}