Help me implement a look up table in C

[nrmlguru0308]

Hello,

In one of my application I need to implement a look up table in C.

I have attache the lookup table.

I need to pick the data depending on two variable parameters x and y.

for exaple if x=10 and y=4 then I have to pick 32.

Thanks in advance

 

[bassa]

Re: Look up table in C



You may check this

#define NUMBER_OF_ROWS 5
#define NUMBER_OF_COLS  4

static int myArray[NUMBER_OF_ROWS][NUMBER_OF_COLS] =
{
{5, 10, 15, 20},
{12, 10, 8, 8},
{24, 22, 20, 18},
{34, 32, 30, 29},
{46, 43, 43, 43}
};

void main(void)
{ int i, j;
printf("\n The contents of myArray are:\n");
for (i = 0; i < NUMBER_OF_ROWS; i++)
{ for(j = 0; j < NUMBER_OF_COLS; j++)
printf("%5d", myArray[i][j]);
printf("\n");
}
}

But, since your rows and colums are not in sequence, so you may have either full lookup table (10 rows, 20 colums) or you need to divide your X and Y by specific value (rows divide by 2, colums divide by 5) to access the table


regards
bassa

 

[BurnOut_tesla]

Re: Look up table in C

since ur index is periodic u can use following statement....
myArray[(x/5) - 1][(y/2) - 1];
ur x will have value 5, 10, 15, 20
& y will have value 2, 4, 8, 10

LookUp table will be like this
code unsigned char myArray[][] = {
{ 46, 34, 24, 12 },
{ 43, 32, 22, 10 },
{ 43, 30, 20, 8 },
{ 43, 29, 18, 8 }
};

 

[nrmlguru0308]

Re: Look up table in C

Thanks a lot guys.....

Added after 34 minutes:

Hello Guys,

If the index is not periodic then do i need to use enum?

If for example
x values are 0,5,10,20,25,30
y values are 50,60,70,80,90,95

Thanks in advance,

 

[BurnOut_tesla]

Re: Look up table in C

very good use of enum....
:idea: