Examples+
Loading Tabular Data
by Daniel Shiffman
This example demonstrates how to use loadTable() to retrieve data from a CSV file and make objects from that data. Here is what the CSV looks like: x,y,diameter,name 160,103,43.19838,Happy 372,137,52.42526,Sad 273,235,61.14072,Joyous 121,179,44.758068,Melancholy
Highlighted Features
/**
* Loading Tabular Data
* by Daniel Shiffman.
*
* This example demonstrates how to use loadTable()
* to retrieve data from a CSV file and make objects
* from that data.
*
* Here is what the CSV looks like:
*
x,y,diameter,name
160,103,43.19838,Happy
372,137,52.42526,Sad
273,235,61.14072,Joyous
121,179,44.758068,Melancholy
*/
// An Array of Bubble objects
Bubble[] bubbles;
// A Table object
Table table;
void setup() {
size(640, 360);
loadData();
}
void draw() {
background(255);
// Display all bubbles
for (Bubble b : bubbles) {
b.display();
b.rollover(mouseX, mouseY);
}
textAlign(LEFT);
fill(0);
text("Click to add bubbles.", 10, height-10);
}
void loadData() {
// Load CSV file into a Table object
// "header" option indicates the file has a header row
table = loadTable("data.csv", "header");
// The size of the array of Bubble objects is determined by the total number of rows in the CSV
bubbles = new Bubble[table.getRowCount()];
// You can access iterate over all the rows in a table
int rowCount = 0;
for (TableRow row : table.rows()) {
// You can access the fields via their column name (or index)
float x = row.getFloat("x");
float y = row.getFloat("y");
float d = row.getFloat("diameter");
String n = row.getString("name");
// Make a Bubble object out of the data read
bubbles[rowCount] = new Bubble(x, y, d, n);
rowCount++;
}
}
void mousePressed() {
// Create a new row
TableRow row = table.addRow();
// Set the values of that row
row.setFloat("x", mouseX);
row.setFloat("y", mouseY);
row.setFloat("diameter", random(40, 80));
row.setString("name", "Blah");
// If the table has more than 10 rows
if (table.getRowCount() > 10) {
// Delete the oldest row
table.removeRow(0);
}
// Writing the CSV back to the same file
saveTable(table, "data/data.csv");
// And reloading it
loadData();
}
// A Bubble class
class Bubble {
float x,y;
float diameter;
String name;
boolean over = false;
// Create the Bubble
Bubble(float x_, float y_, float diameter_, String s) {
x = x_;
y = y_;
diameter = diameter_;
name = s;
}
// CHecking if mouse is over the Bubble
void rollover(float px, float py) {
float d = dist(px,py,x,y);
if (d < diameter/2) {
over = true;
} else {
over = false;
}
}
// Display the Bubble
void display() {
stroke(0);
strokeWeight(2);
noFill();
ellipse(x,y,diameter,diameter);
if (over) {
fill(0);
textAlign(CENTER);
text(name,x,y+diameter/2+20);
}
}
}
Related Examples
This example is for Processing 4+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.