static BWImage bwImageFromColumnFloats(float[] cols) {
  ret bwImageFromColumnFloats(cols, 20);
}

static BWImage bwImageFromColumnFloats(float[] cols, int h) {
  if (empty(cols) || h <= 0) null;
  int w = l(cols);
  BWImage bw = new(w, h);
  for x to w: {
    float f = cols[x];
    for y to h:
      bw.setPixel(x, y, f);
  }
  ret bw;
}

static BWImage bwImageFromColumnFloats(int h, float[] cols) {
  ret bwImageFromColumnFloats(cols, h);
}