title: Rounding of Double value without decimal points in spark Dataframe
body: <p>I tried to round off a double value without decimal points in spark dataframe but same value is obtained at the output.</p>
  
  <p>Below is the dataframe column value .</p>
  
  <pre><code>+-----+-----+
  | SIG1| SIG2|
  +-----+-----+
  | 46.0| 46.0|
  | 94.0| 46.0|
  </code></pre>
  
  <p>The schema for the dataframe column is as below.</p>
  
  <pre><code>scala&gt; df.printSchema
  root
   |-- SIG1: double (nullable = true)
   |-- SIG2: double (nullable = true)
  </code></pre>
  
  <p>The expected output is as below</p>
  
  <pre><code>+-----+-----+
  | SIG1| SIG2|
  +-----+-----+
  | 46  |   46|
  | 94  |   46|
  </code></pre>
  
  <p>I have tried rounding of column as below as per the document </p>
  
  <pre><code>+------------------------------------------------------------------+
  |ReturnType| Signature     |                            Description|
  +------------------------------------------------------------------+
  |DOUBLE    |round(DOUBLE a)| Returns the rounded BIGINT value of a.|
  </code></pre>
  
  <p>the code used is </p>
  
  <pre><code>val df1 = df.withColumn("SIG1", round(col("SIG1"))).withColumn("SIG2", round(col("SIG2")))
  </code></pre>
  
  <p>Do we need to cast the column into int/bigint  or is it possible with round function itself?</p>
  
  <p>Thanks in advance!</p>