title: Plot all rows of a data frame with ggplot
body: <p>I ham fairly new to R and I might have a rather "stupid question" here.</p>
  
  <p>I have a data frame that consists multiple measurements of 10 sensors (named X1,X2,...X10). Each row number indicates the the trial number. So for example if we assume we have 7 trials then the data frame looks something like this:</p>
  
  <pre><code>    X1  X2  X3  X4  X5  X6  X7  X8  X9  X10
  1   5   2   6   0   10  10  3   1   8   9
  2   1   2   2   10  1   0   8   2   5   5
  3   9   0   0   8   7   9   10  3   3   5
  4   10  9   5   6   7   9   0   9   8   6
  5   1   4   2   4   3   10  8   0   1   7
  6   5   2   10  7   6   0   4   1   8   7
  7   10  2   2   1   4   3   2   4   6   2
  </code></pre>
  
  <p>I want to plot all the rows together. For example for the first trial x will be 1:10 and y is the first row of the data frame.</p>
  
  <p>I know some ways to do this but how can I use ggplot to do this ?
  Thanks</p>