selecting an element of a vector

How to select an element of a vector which is nearest to the given value xp.

Suppose we have a vector

x=[1 1.05 1.1 1.15 1.2 1.25]  

a) if xp=1.18, the output should be 1.2 (which is nearest to 1.18)
b) if xp=1.12, the output should be 1.1 (which is nearest to 1.12)

[madhan ravi]

b) if xp=1.12, the output should be 1.1 (which is nearest to 1.12)

nearest to 1.12 is 1.15 ?? not 1.1 , whats the logic behind it ,explain to understand

[PJS KUMAR]

1.1 is nearest to 1.12 than 1.15

Answer 1

[KALYAN ACHARJYA]

x=[1 1.05 1.1 1.15 1.2 1.25];
xp=input('Enter the xp value: ');  
[d, idx]=min(abs(x-xp));
fprintf('The output is%.2f',x(idx));

Command Window

Enter the xp value: 1.18
The output is1.20

[PJS KUMAR]

What is [d, idx]

[KALYAN ACHARJYA]

idx is giving the index position of x, which is close to xp

if idx=1, that means x(idx)=x(1)=1 (First element)

d gives the minimum difference of x-xp, abs absolute value (+ve)

Answer 2

[PJS KUMAR]

How to select an element of a vector which is previous to the given value xp.

Suppose we have a vector

x=[1 1.05 1.1 1.15 1.2 1.25]  
a) if xp=1.18, the output should be 1.15 (which is previous to 1.18)
b) if xp=1.12, the output should be 1.1 (which is previous to 1.12)