picking numbers with specific difference in matlab

I have a data set...like say CAD from 212 to 550 say with a differnce of 1 and have corresponing SA values to these CAD values

But I want to pick numbers at a specific distance and in a specific sequence ..like 212,212.3,212.7,213,213.3,213.7.....so that later on i can interpolate the SA values on these CAD values.

How can i do that!! if there was single difference between numbers that would be simple as i did here picking data with a differenc of 0.5:

CAD= data(:,1);

SA= data(:,2);

CADQ=CAD(1):0.5:CAD(end);

vq = interp1 (CAD, SA, CADQ);

here i was able to pick 212,212.5,213,213.5....and was able to interpolate SA on these CAD values.

now how can i do that..picking CAD data in the sequence 212,212.3,212.7,213,213.3,213.7,214,214.3.....

[Rik]

I don't understand your question well enough to answer it, but it sounds as if ismember will be helpful.

Answer 1

[Steven Lord]

One way is to take advantage of implicit expansion.

x = 212:215;
y = [0; 0.3; 0.7];
z = reshape(x+y, 1, [])

z = 1×12

212.0000 212.3000 212.7000 213.0000 213.3000 213.7000 214.0000 214.3000 214.7000 215.0000 215.3000 215.7000

[Usama Bin Khalid]

Its working for the instance but its not following the sequence...you understand what i mean,...i.e if i put here

[ 0;0.3;0.8 ], it will generate 212 212.3 212.8 213 213.3 213.8

but i wanted was to follow like this

212 212.3 212.8 213.1 213.6 213.9.... like addition of 0.3 then 0.5 then 0.3 then 0.5...

ok i will uplaod a sample data here: .. and re-question my question:

I want to get values of SA at CAD 213,213.3,213.7,214,214.3,214.7,215,215.3.....so on...just on these points.. so when i will get these i will interpolate SA values on them

CAD SA.

213 0.028698539

213.46 0.028679289

213.76 0.028659992

214.46 0.028640648

214.76 0.028621256

215.46 0.028601818

215.76 0.028582333

216.46 0.028562802

216.76 0.028543223

so on.....

if i implement your code it will give the values that i dont need like it will start adding 0.3,0.4 into 213.46 and so on.. i hope now my question is understadable..

[Rik]

repmat with cumsum should do the trick.

[Usama Bin Khalid]

please elaboarte with a code or algorithm..that will be helpful...

[Rik]

Create an array where you repeat 0.3 0.5 enough times, set your starting offset as the first value and then use cumsum to calculate the cumulative sum.

x=repmat([0.3 0.5],1,5)

x = 1×10

0.3000 0.5000 0.3000 0.5000 0.3000 0.5000 0.3000 0.5000 0.3000 0.5000

x(1)=213

x = 1×10

213.0000 0.5000 0.3000 0.5000 0.3000 0.5000 0.3000 0.5000 0.3000 0.5000

x=cumsum(x)

x = 1×10

213.0000 213.5000 213.8000 214.3000 214.6000 215.1000 215.4000 215.9000 216.2000 216.7000

[Usama Bin Khalid]

Yes it worked perfectly...so we can use this code to interpolate any repetitive values....Thanks