Two Dimensional Data

String[] countries; 

float[][] countriesValues; // Two-dimensional array. Stores an array of values for each country

String[] yearNames;  // Store the name of the years

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void setup() {

  size(500, 500);

  smooth();

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  /* Read data */

  String lines[] = loadStrings("data.csv");

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  String firstLine = lines[0];

  String[] firstLinePieces = split(firstLine, ";");

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  /* Initialize arrays to hold the data */

  int numberOfCountries = lines.length - 1;  // Skip first row 

  int numberOfYears = firstLinePieces.length  - 1;

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  countries = new String[numberOfCountries];

  countriesValues = new float[numberOfCountries][numberOfYears];

  yearNames = new String[numberOfYears];

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  /* Read the first line (name of the years) separately */

  for (int i = 0; i < numberOfYears; i++) {

    yearNames[i] = firstLinePieces[i+1];  // +1 because first field is empty

  }

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  /* Go through the file line by line */

  for (int i = 0; i < numberOfCountries; i++) {

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    String line = lines[i+1];

    String[] pieces = split(line, ";");

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    countries[i] = pieces[0]; 

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    for (int j = 0; j < numberOfYears; j++) {

      countriesValues[i][j] = float(pieces[j + 1]);

    }

  }

} 

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​

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void draw() {

  background(0);

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  stroke(128);

  noFill();

  strokeWeight(1);

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  /* Draw a grid with the years */

  for (int i = 0; i < yearNames.length; i++) {

    float x = map(i, 0, yearNames.length - 1, 0, width);

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    line(x, 50, x, height);

    pushMatrix();

    text( yearNames[i],x, 20.0);

    popMatrix();

  }

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  /* Draw the values (connected) for each country */

  strokeWeight(3);

  stroke(255);

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  for (int i = 0; i < countries.length; i++) {

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    beginShape();

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    float[] values = countriesValues[i];

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    for (int j = 0; j < values.length; j++) {

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      float x = map(j, 0, values.length - 1, 0, width);

      float valueHeight = height - values[j] * 10;

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      vertex(x, valueHeight);

    }

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    endShape();

  }

}

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