Finding Upper and Lower Indexes

Hello,

I have 2 vectors:

A = [1;2;3;4;5;8];

B = [3.5;6;2];

I would like to find the lower and upper indexes and store in another array C. C should be =

C = [3 4;5 6;2 0]; where first column represent the lower index and second column represent the upper index. In case an exact data is found lower index gives the index directly]

for example: 3.5 is between 3 & 4 so in C first row becomes 3 4.

Could you please help me in this?

Thanks.

Answer 1

[Matt J]

A = [1;2;3;4;5;8];
B = [3.5;6;2];

c=interp1(A,A,B,'previous');
C=[c(:),c(:)+1]

C = 3×2

3 4 5 6 2 3