CODEWITHSUNDEEP
jsond3.jsmax
Le Sparte
Le Sparte

Reputation: 163

D3 : best way to find max value in a JSON object

What's the best way to find the maximum value of n2 (450) in this dataJSON3 object using d3.js? 

var dataJSON3 = {
  set1 : [
    {"nom":"Allemagne", "n1":200, "n2":86, "n3": 30},
    {"nom":"Allemagne", "n1":120, "n2":156, "n3": 40},
    {"nom":"France", "n1":117, "n2":34, "n3": 35},
    {"nom":"Italie", "n1": 309, "n2":12, "n3": 6},  
  ],  
  set2 : [
    {"nom":"Suisse", "n1":60, "n2":86, "n3": 30},
    {"nom":"Allemagne", "n1":90, "n2":450, "n3": 40},
    {"nom":"France", "n1":1000, "n2":34, "n3": 35},
    {"nom":"Italie", "n1": 440, "n2":12, "n3": 6},  
  ]
}

Upvotes: 2

Views: 3202

Answers (1)

iulian
iulian

Reputation: 5822

If you want to find the max of exactly this json structure, you can do it like this: 

var maxValue = d3.max([  // Find the max value of a list of 2 elements
    d3.max(dataJSON3.set1, function(d) { return d.n2; }), // Find the max value in `set1`
    d3.max(dataJSON3.set2, function(d) { return d.n2; })  // Find the max value in `set2`
]);

For a dynamic number of sets, you'll need to iterate through each property, find its max value and then find the max values among each property's max value:

var maxValuesPerSet = [];
for (var property in dataJSON3) {
    if (object.hasOwnProperty(property)) {
        maxValuesPerSet.push(d3.max(dataJSON3[property], function(d) { return d.n2; }));
    }
}
var maxValue = d3.max(maxValuesPerSet);

Upvotes: 3

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