processing4/java/examples/Books/Visualizing Data/ch04-milkteacoffee/step_17_interpolate/FloatTable.pde

// first line of the file should be the column headers
// first column should be the row titles
// all other values are expected to be floats
// getFloat(0, 0) returns the first data value in the upper lefthand corner
// files should be saved as "text, tab-delimited"
// empty rows are ignored
// extra whitespace is ignored


class FloatTable {
  int rowCount;
  int columnCount;
  float[][] data;
  String[] rowNames;
  String[] columnNames;
  
  
  FloatTable(String filename) {
    String[] rows = loadStrings(filename);
    
    String[] columns = split(rows[0], TAB);
    columnNames = subset(columns, 1); // upper-left corner ignored
    scrubQuotes(columnNames);
    columnCount = columnNames.length;

    rowNames = new String[rows.length-1];
    data = new float[rows.length-1][];

    // start reading at row 1, because the first row was only the column headers
    for (int i = 1; i < rows.length; i++) {
      if (trim(rows[i]).length() == 0) {
        continue; // skip empty rows
      }
      if (rows[i].startsWith("#")) {
        continue;  // skip comment lines
      }

      // split the row on the tabs
      String[] pieces = split(rows[i], TAB);
      scrubQuotes(pieces);
      
      // copy row title
      rowNames[rowCount] = pieces[0];
      // copy data into the table starting at pieces[1]
      data[rowCount] = parseFloat(subset(pieces, 1));

      // increment the number of valid rows found so far
      rowCount++;      
    }
    // resize the 'data' array as necessary
    data = (float[][]) subset(data, 0, rowCount);
  }
  
  
  void scrubQuotes(String[] array) {
    for (int i = 0; i < array.length; i++) {
      if (array[i].length() > 2) {
        // remove quotes at start and end, if present
        if (array[i].startsWith("\"") && array[i].endsWith("\"")) {
          array[i] = array[i].substring(1, array[i].length() - 1);
        }
      }
      // make double quotes into single quotes
      array[i] = array[i].replaceAll("\"\"", "\"");
    }
  }
  
  
  int getRowCount() {
    return rowCount;
  }
  
  
  String getRowName(int rowIndex) {
    return rowNames[rowIndex];
  }
  
  
  String[] getRowNames() {
    return rowNames;
  }

  
  // Find a row by its name, returns -1 if no row found. 
  // This will return the index of the first row with this name.
  // A more efficient version of this function would put row names
  // into a Hashtable (or HashMap) that would map to an integer for the row.
  int getRowIndex(String name) {
    for (int i = 0; i < rowCount; i++) {
      if (rowNames[i].equals(name)) {
        return i;
      }
    }
    //println("No row named '" + name + "' was found");
    return -1;
  }
  
  
  // technically, this only returns the number of columns 
  // in the very first row (which will be most accurate)
  int getColumnCount() {
    return columnCount;
  }
  
  
  String getColumnName(int colIndex) {
    return columnNames[colIndex];
  }
  
  
  String[] getColumnNames() {
    return columnNames;
  }


  float getFloat(int rowIndex, int col) {
    // Remove the 'training wheels' section for greater efficiency
    // It's included here to provide more useful error messages
    
    // begin training wheels
    if ((rowIndex < 0) || (rowIndex >= data.length)) {
      throw new RuntimeException("There is no row " + rowIndex);
    }
    if ((col < 0) || (col >= data[rowIndex].length)) {
      throw new RuntimeException("Row " + rowIndex + " does not have a column " + col);
    }
    // end training wheels
    
    return data[rowIndex][col];
  }
  
  
  boolean isValid(int row, int col) {
    if (row < 0) return false;
    if (row >= rowCount) return false;
    //if (col >= columnCount) return false;
    if (col >= data[row].length) return false;
    if (col < 0) return false;
    return !Float.isNaN(data[row][col]);
  }


  float getColumnMin(int col) {
    float m = Float.MAX_VALUE;
    for (int row = 0; row < rowCount; row++) {
      if (isValid(row, col)) {
        if (data[row][col] < m) {
          m = data[row][col];
        }
      }
    }
    return m;
  }


  float getColumnMax(int col) {
    float m = -Float.MAX_VALUE;
    for (int row = 0; row < rowCount; row++) {
      if (isValid(row, col)) {
        if (data[row][col] > m) {
          m = data[row][col];
        }
      }
    }
    return m;
  }

  
  float getRowMin(int row) {
    float m = Float.MAX_VALUE;
    for (int col = 0; col < columnCount; col++) {
      if (isValid(row, col)) {
        if (data[row][col] < m) {
          m = data[row][col];
        }
      }
    }
    return m;
  } 


  float getRowMax(int row) {
    float m = -Float.MAX_VALUE;
    for (int col = 0; col < columnCount; col++) {
      if (isValid(row, col)) {
        if (data[row][col] > m) {
          m = data[row][col];
        }
      }
    }
    return m;
  }


  float getTableMin() {
    float m = Float.MAX_VALUE;
    for (int row = 0; row < rowCount; row++) {
      for (int col = 0; col < columnCount; col++) {
        if (isValid(row, col)) {
          if (data[row][col] < m) {
            m = data[row][col];
          }
        }
      }
    }
    return m;
  }


  float getTableMax() {
    float m = -Float.MAX_VALUE;
    for (int row = 0; row < rowCount; row++) {
      for (int col = 0; col < columnCount; col++) {
        if (isValid(row, col)) {
          if (data[row][col] > m) {
            m = data[row][col];
          }
        }
      }
    }
    return m;
  }
}