read csv/tsv with no header line in D3

Question

I have CSV data which looks something like:

Data

1,1,10
1,2,50
1,3,5
etc...

And I am trying to read in the data. However, my initial data does not contain a header row (as seen above) so it is taking the first data row to be the header (1,1,10). Is there anyway around this. I want to set the header names after I read the data

Javascript

d3.csv("data/testnh.csv", function(data) {
    console.log(data);
}

Thanks!

Answer 1

Use d3.text to load the data, and then d3.csvParseRows to parse it. For example:

d3.text("data/testnh.csv", function(text) {
  console.log(d3.csvParseRows(text));
});

You'll probably also want to convert your columns to numbers, because they'll be strings by default. Assume they are all numbers, you could say:

d3.text("data/testnh.csv", function(text) {
  var data = d3.csvParseRows(text).map(function(row) {
    return row.map(function(value) {
      return +value;
    });
  });
  console.log(data);
});

Answer 2

Since Bostock's answer in 2012, d3.csv.parseRows allows for an optional accessor function, which enables his answer to be expressed more concisely:

d3.text("data/testnh.csv", function(text) {
    var data = d3.csv.parseRows(text, function(d) {
        return d.map(Number);
    });
    // Now do something with data
});

Answer 3

first read in data using d3.text, then add custom header string, then parse the result with d3.csv.parse

d3.text("data/testnh.csv", function(r){
   var result = "x, y, z\n" + r;  //now you have the header
   var data = d3.csv.parse(result);
   //do your plotting with data
}

Answer 4

Try d3.csvParse(text)

d3.csv.parseRows seems doesn't work in modern d3 version.