D3

Loading Data

To load multiple (arbitrary number) CSV files:

var filesArray = ["myrandedata.csv","myrandndata.csv","myrandudata.csv"];                

var remaining = filesArray.length;                                                       

// from https://groups.google.com/forum/#!msg/d3-js/3Y9VHkOOdCM/YnmOPopWUxQJ             
filesArray.forEach( function(f) {                                                        
    d3.csv(f, function(data) {                                                           
        mydata[f] = data;
        if (!--remaining) doSomething();                                                 
    });                                                                                  
});                                                                                      

function doSomething() {
    filesArray.forEach( function(f) {                                                    
        console.log( mydata[f] );                                                        
    });                                                                                  
}

Things I learned about D3 while modifying Parallel example

• Role of maps
• Nesting functions
• Scope of Javascript
• How to use for loops instead of functions to avoid scope issues
• How to load multiple files using a counter to avoid scope/asynchronous issues
• The whole function notation
• Loading data as CSV (associated array) or as text (plain multidimensional array)
• Console
• Accessing arrays using notation data[0] versus data['x1'] versus data.x1
• Notation +p[d]