math.atan

math.atan　値に逆正接を返す。

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-- math.atan　標準ライブラリ（数学関数） atan_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.atan　サンプル", 10, 4, 24, C_Black)
 
  -- グラフ描画
  canvas.drawLine( 150,100 - 20, 150, 200 + 20, C_Blue)  -- 縦軸メイン
  canvas.drawLine( 50 - 20, 150, 250 + 20, 150, C_Blue)  -- 横軸メイン
  for y = 100, 200, 50 do  -- 縦軸目盛
      canvas.drawLine( 145,y, 155, y, C_Blue)
  end
  for x = 50, 250, 20 do  -- 横軸目盛
      canvas.drawLine( x, 145, x, 155, C_Blue) 
  end
  canvas.drawText("-5", 45, 155, 12, C_Black)
  canvas.drawText("-4", 65, 155, 12, C_Black)
  canvas.drawText("-3", 85, 155, 12, C_Black)
  canvas.drawText("-2", 105, 155, 12, C_Black)
  canvas.drawText("-1", 125, 155, 12, C_Black)
  canvas.drawText("0", 140, 155, 12, C_Black)
  canvas.drawText("1", 168,  155, 12, C_Black)
  canvas.drawText("2", 188,  155, 12, C_Black)
  canvas.drawText("3", 208,  155, 12, C_Black)
  canvas.drawText("4", 228,  155, 12, C_Black)
  canvas.drawText("5", 248,  155, 12, C_Black)
  canvas.drawText("-1", 135, 95, 12, C_Black)
  canvas.drawText("1", 135, 195, 12, C_Black)
 
  for Rad = -5, 5, 0.1 do
 
    canvas.drawCircle( Rad * 20 + 150, math.atan(Rad) * -50 + 150, 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.atanのサンプルの実行結果です。

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