title: Create a variable number of `sliderInput` in Shiny
body: <p>My data is a matrix with a variable number of columns. Also , the range of values within the matrix is variable, too.
  I want to build a variable number of <code>sliderInput</code>, each corresponding to one column in the matrix. 
  The higher limit of each slider should correspond to the <code>maxRange</code> within the matrix.
  Any suggestion how to do it in one shot?</p>
  
  <pre><code> lapply(1:ncol, function(i) {
          sliderInput(
            paste0('a', i), 
            paste0('SelectA', i),
            min = min(c(1:maxRange)),
            max = max(c(1:maxRange)),
            value = c(1, maxRange),
            step =1
            )
        }
        )
  </code></pre>