在多维数组中查找最接近Embedded C中给定值的值

Question

I am developing an embedded colour sensing application with a microcontroller and a colour sensor using the C programming language.

At the moment, I have an array with calibration values that looks something like this (Each row is a calibration for a different thing)

unsigned long calibrationValues[6][6]

value1 value2 value3 value4 value5 value6    
value1 value2 value3 value4 value5 value6
value1 value2 value3 value4 value5 value6
value1 value2 value3 value4 value5 value6
value1 value2 value3 value4 value5 value6
value1 value2 value3 value4 value5 value6

and another array

unsigned long scannedValue[6]

that holds six values that have been scanned for analysis against the calibration values

I know how I would check to see if the value exists within the array, but that is way too specific for what I would like to do as the value being scanned in for analysis could differ slightly to the exact calibrated value

So, my question is: How would I find the index of the result in the calibrationValues row that is the closest to the scannedValue value?

Example

(values used below are just for example)

calibrationValues[6][6]

0 - 100 250 325 650 700 830
1 - 5   12  15  35  50  90
2 - ...
...

scannedValue[6]
0 - 350
1 - 80
2 - ...
...

scannedValue[0] is closest to calibrationValues[0][2]
scannedValue[1] is closest to calibrationValues[1][5]
...
etc

I have looked at other questions, in particular this question but not sure how to adapt to a multidimensional array

Answer 1

Assuming this is as straight forward as it sounds:

int i, j;
int results[6];
int minDiff, diff;

for (i = 0; i < 6; ++i)
{
    results[i] = 0; 
    minDiff = abs(scannedValue[i] - calibrationValues[i][0]);

    for (j = 1; j < 6; ++j)
    {
        diff = abs(scannedValue[i] - calibrationValues[i][j]);
        if (diff < minDiff)
        {
            minDiff = diff;
            results[i] = j;
        }
    }
}

The results[] array will contain the closest index from 0 to 5.