title: Σ Calculation in iOS SDK
body: <p>I am working on a financial app where I have to perform a calculation. Finance team provide me below formula for calculation as below image</p>
  
  <p>[![enter image description here][1]][1]</p>
  
  <p>But I am unable to found how to perform below operation in Swift or Objective-C.</p>
  
  <pre><code>     n      t-1
       Σ (1+i)
       t=1
  </code></pre>
  
  <p>Can you please help me providing an idea of the above calculation? </p>
  
  <p>I also read this <a href="http://cocoadocs.org/docsets/SigmaSwiftStatistics/3.0.1/" rel="nofollow noreferrer">link</a> but not interested to use the third party.</p>