Cannot call value of non-function type double
<p>I am quite new to programing in swift and I am working on a music app for iOS that adjusts the font size of the text in a UILabel in proportion to the string's length. In my code, I am trying to count the number of characters in the string statement and have it plugged into a formula, but for some reason Xcode gives me the error: <strong>Cannot call value of non function type double</strong> I tried setting the value to a CGFloat but it still gives me the same error on the "let b = 41.2 - .8(a) line. Thank you so much and sorry if this seems like a basic question.</p>

<pre><code>let title = "Let It Bleed"
    AlbumName.text = title
    let a  = title.characters.count

   if ( a &lt;= 19){

    let b = 41.2 - .8(a)
        let fontsize = CGFloat(b)
       AlbumName.font = AlbumName.font.fontWithSize(fontsize)

    }
</code></pre>

<p><a href="http://i.stack.imgur.com/KFuYS.png" rel="nofollow">A screenshot of the code with the error</a></p>