substitute if long statements by word or letter

Hi guys;

please can any one tell me if I can substitute the long next if statement by one letter or word because I use it a lot in my code.

if  ((sigma{1}(1))^2/((SL(1))^2))-(sigma{1}(1)*sigma{1}(2)/((SL(1))^2))+((sigma{1}(2))^2/((ST(1))^2))+((sigma{1}(3))^2/(SLT)^2)>=1....
      ||((sigma{2}(1))^2/((SL(2))^2))-(sigma{2}(1)*sigma{2}(2)/((SL(2))^2))+((sigma{2}(2))^2/((ST(2))^2))+((sigma{2}(3))^2/(SLT)^2)>=1....
      ||((sigma{3}(1))^2/((SL(3))^2))-(sigma{3}(1)*sigma{3}(2)/((SL(3))^2))+((sigma{3}(2))^2/((ST(3))^2))+((sigma{3}(3))^2/(SLT)^2)>=1....
      ||((sigma{4}(1))^2/((SL(4))^2))-(sigma{4}(1)*sigma{4}(2)/((SL(4))^2))+((sigma{4}(2))^2/((ST(4))^2))+((sigma{4}(3))^2/(SLT)^2)>=1
  break;end

Answer 1

[Walter Roberson]

Write a function (or function handle) and pass it sigma and SL and ST and SLT.

You can subdivide it into two parts, as the pattern of indices is regular

F1 = @(K,sigma,SL,ST,SLT) sigma{K}(1))^2/((SL(K))^2 <etc> >=1
F2 = @(sigma,SL,ST,SLT) F1(1,sigma,SL,ST,SLT) || F1(2,sigma,SL,ST,SLT) || F1(3,sigma,SL,ST,SLT) || F1(4,sigma,SL,ST,SLT)

[Abdulaziz]

I tried to but F2 in if statement but it was wrong the message is (Conversion to logical from function_handle is not possible.) should I put any thing with the F2 that contains all the conditions.

I appreciate your time and help

[Walter Roberson]

You would use

if F2(sigma,SL,ST,SLT)

Answer 2

[Abdulaziz]

Thank you very much Walter Roberson your answers always the best and must clear and specified.

I really appreciate your time.

Best, Aziz