To replace row number and column number with a specified value in a mat file

I have a mat file where row represent latitude and column represent longitude. Like row 1 and column 2 will have data on latitude 34.5N and 65.5 E. Instead of giving value of row number and column number to det the value at particular row and column i want to input the corresponding latitude and longitude value. How can it be done . Please help

Answer 1

[KSSV]

Read about knnsearch. This will give you the required indices.