How to interpolate to the nearest value

HI

I have vector, v=(x,Y) and I want to find the nearest value of 'x' for C=(1,yi) rather than the interpolated values of xi's .I can find the interpolated value but taking the nearest values of x is difficult for me. Can you help me with this?

Answer 1

[Kelly Kearney]

If you look at the documentation of interp1, you'll see that nearest neighbor interpolation is an option:

interp1(x,y,xi, 'nearest')

[Ede gerlderlands]

Thank you.

Answer 2

[Pourya Alinezhad]

here is the answer to your question. :) t = 1900:10:1990; >> p = [75.995 91.972 105.711 123.203 131.669... 150.697 179.323 210.212 256.505 270.633];

>> interp1(t,p,1975) ans = 233.3585

[Ede gerlderlands]

yes, but what I want is the nearest value not the interpolated one. In the example you give me the nearest value to 233.358 is ' 210.212' and I want this value. Thanks

[Pourya Alinezhad]

so you must write some line of codes .at first interpolate the value like that aforesaid.then subtract the result from upper and lower values in the vector.the smaller answer of subtraction is the nearest.

[Ede gerlderlands]

yes, am new to matlab and find it difficult

[Pourya Alinezhad]

so you can do in an other way : x=[ 1 8 35 ...] y=[ 23 55 3 ...] for example we want nearest value to x=8;

a=find(x,8);
min=inf;
num_min=[];
  for i=1:length(x)
     if abs(y(a)-y(i))<min
       min=abs(y(a)-y(i));
       num_min=i;
      end
      end