How find the best step for the array.

Hello,

I have following array:

first_tt= 1;step = 7;last_tt = 27; 
tt= first_tt:step:last_tt; 

Answer: 
tt= [1,8,15,22];

So what I want is to include the last number 27, by slightly changing the step, BUT still meet the second array value of original array, in this case 1+7= 8. tt= [1, 8,15,22];

Currently done:

first_tt= 1; step = 7;last_tt = 27; tt= first_tt:step:last_tt; new_step = (last_tt-first_tt)/length(tt); new_tt= first_tt:new_step:last_tt;

Answer:

new_tt = [1,7.5,14,20.5,27];

So what I need is to include second array value of original array, i.e 8, so I'm wondering, if there are any ways of doing it?

new_tt = [1,..., *8 (?)*,....,27];

Even +/-2% would be ok.

i.e

new_tt = [1,..., *7.84 (?)*,....,26.46];

Best Regards,

Ivan

[Ced]

EDIT moved to answer section.

[Ivan Shorokhov]

@Ced, Great, thank you, could you please add your comment in the answer section, so I can select it as the best one.

[Ced]

Glad it helped. Done, thanks!

Answer 1

[Ced]

You need to decide whether you want equidistant steps, or matching numbers.

I'm sure I'm missing something, but if you just want the second and last, then

tt = first_tt:step:last_tt;
if ( tt(end) < last_tt )
   tt(end+1) = last_tt;
end

Or, if you only need to match the two numbers, then:

first_tt= 1;step = 7;last_tt = 27; 
second_tt = first_tt + step;
n_elements = floor((last_tt-second_tt)/step)+1;

tt = linspace(second_tt,last_tt,n_elements);

The point is, there are a million ways of doing this, but none of them will manage to go from one number to another in equidistant steps without some other compromise.