static BufferedImage simpleGraph(int w, int h, IF1<Int, Double> f, double fMin, double fMax) {
  BufferedImage graph = whiteImage(w, h);
  double graphScale = doubleRatio(1, fMax);
  int zeroY = iround(transformBetweenDoubleRanges(0, doubleRange(fMin, fMax), doubleRange(h-1, 0)));
  for (int x = 0; x < w; x++)
    drawLine(graph, x, zeroY, x,
      iround(transformBetweenDoubleRanges(f.get(x), doubleRange(fMin, fMax), doubleRange(h-1, 0))), Color.red);
  ret graph;
}