MATLAB: Rounding each individual value in a vector to values in another vector

Question

If you have v1 = [2.5 3.74 7.92] (These numbers are meant to be random) and you wanted to round these numbers up or down, you use floor(v1) or ceil(v1). But what if you wanted to round these numbers to other values instead of integers? Say you want to round them to the values in vector v2 = 1.25:10.25. How would you go about doing it without using a for loop?

Such that:

"function"(v1,v2) = [2.25 3.25 7.25] %Rounding to the left "function"(v1,v2) = [3.25 4.25 8.25] %Rounding to the right

I know that one method is

for i = 1:length(v1) v2(find(v1(i)-v2>0,1,'last')); % Nearest lower end

for i = 1:length(v1) v2(find(v1(i)-v2<0,1,'first')); % Nearest higher end

However, this method involves a for loop. Is there a more elegant method with only vectorization involved?

Thanks for your help.

Answer 1

v1 = [2.5 3.74 7.92];
v2 = 1.25:10.25;
interp1(v2, v2, v1, 'nearest')

You can modify the code of INTERP1 to get the next lower or higher values also.