math.exp

math.exp　自然対数の底のべき乗を返す。

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-- math.exp　標準ライブラリ（数学関数） exp_sample.lua
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function main()
 
  C_Black = color( 0, 0, 0)       -- 黒
  C_White = color(255, 255, 255)  -- 白
  C_Blue = color( 0, 0, 255)      -- 青
  C_Red = color(255, 0, 0)        -- 赤
 
  -- メイン画面サイズを変更
  canvas.setMainBmp(500,300)
 
  canvas.drawCls(C_White)
  canvas.drawText("math.exp　サンプル", 10, 4, 24, C_Black)
 
   -- グラフ描画
  canvas.drawLine( 150,50, 150, 200 + 20, C_Blue)  -- 縦
  canvas.drawLine( 50 - 20,200, 190 + 20, 200, C_Blue)  -- 横
  for y = 0, 150, 30 do
      canvas.drawLine( 145,y + 50, 155, y + 50, C_Blue)  -- 縦
  end
  for x = 0, 140, 20 do
      canvas.drawLine( x + 50, 195, x + 50, 205, C_Blue)  -- 縦
  end
 
  canvas.drawText("-5", 44, 206, 12, C_Black)
  canvas.drawText("-4", 64, 206, 12, C_Black)
  canvas.drawText("-3", 84, 206, 12, C_Black)
  canvas.drawText("-2", 104, 206, 12, C_Black)
  canvas.drawText("-1", 124, 206, 12, C_Black)
  canvas.drawText(" 0", 138, 206, 12, C_Black)
  canvas.drawText(" 1", 164, 206, 12, C_Black)
  canvas.drawText(" 2", 184, 206, 12, C_Black)
  canvas.drawText(" 5", 134, 48, 12, C_Black)
  canvas.drawText(" 4", 134, 78, 12, C_Black)
  canvas.drawText(" 3", 134, 108, 12, C_Black)
  canvas.drawText(" 2", 134, 138, 12, C_Black)
  canvas.drawText(" 1", 134, 168, 12, C_Black)
 
  for x = -5, 1.5, 0.1 do
    canvas.drawCircle( x * 20 + 150, math.exp(x) * -30 + 200, 2,C_Red, 1)
  end
 
  canvas.drawText("画面タッチで終了します。", 10, 280, 16, C_Black)
  touch(3)
 
end
 
main()
 

math.expのサンプルの実行結果です。

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