For loops in R for data compilation

Question

I have a data frame that has a column populated with 0s and 1s. Here is an example of what that data looks like:

0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 0 1 1 0 0 0 0  ... etc.

I need to format the data so that it counts the number of consecutive 0s and 1s, like this:

I'm new to R and am not sure how to do this, but here's how I would do it in JavaScript. I would love some guidance on how to replicate this result in R. Thank you in advance for your help!

var data = [0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0];

var result = [];



for (var i = 0; i < data.length; i++) {

  var item = {};

  item[data[i]] = 1;

  if (!result.length) {

    result.push(item);

  } else {

    var lastItem = result[result.length - 1];

    if (lastItem[data[i]]) {

      lastItem[data[i]] += 1;

    } else {

      result.push(item);

    }

  }

}



console.log(result)

Answer 1

There is a function for that. rle calculates the run-length of each element in the vector. There are two parts to the output, the lengths of the runs, and the values themselves:

rle(x)
#Run Length Encoding
#  lengths: int [1:7] 5 4 10 3 1 2 4
#  values : int [1:7] 0 1 0 1 0 1 0

To create a matrix, we can use:

with(rle(x), cbind(values, lengths))

For loops in R for data compilation

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