我正在编写一个简单的Mathematica实现black-scholes模型,并使用Plot3D绘制定价表面。但是,当我运行此代码时,不会生成任何绘图。我的call
和put
函数在单独运行时生成正确的值,但不生成绘图。代码:
Clear[d1, d2, call, put, stockPrice, strikePrice, riskFreeRate, timeToExp, volatility]
d1[stockPrice_, strikePrice_, riskFreeRate_, timeToExp_, volatility_] := (Log[stockPrice / strikePrice] + (riskFreeRate + 0.5*volatility^2)*timeToExp) / (volatility * Sqrt[timeToExp])
d2[stockPrice_, strikePrice_, riskFreeRate_, timeToExp_, volatility_] := d1[stockPrice, strikePrice, riskFreeRate, timeToExp, volatility] - volatility*Sqrt[timeToExp]
call[stockPrice_, strikePrice_, riskFreeRate_, timeToExp_,
volatility_] := stockPrice * CDF[NormalDistribution[0, 1], d1[stockPrice, strikePrice, riskFreeRate, timeToExp, volatility]] - strikePrice * Exp[-riskFreeRate*timeToExp] *CDF[NormalDistribution[0, 1], d2[stockPrice, strikePrice, riskFreeRate, timeToExp, volatility]]
Plot3D[call[stockPrice, 500, 0.0030, timeToExp, 0.39], {stockPrice,
10, 1000}, {timeToExp, 0.0833333, 5}]
其他情节,如参考样本中的样本,确实有效。
Plot3D[{x^2 + y^2, -x^2 - y^2}, {x, -2, 2}, {y, -2, 2},
RegionFunction -> Function[{x, y, z}, x^2 + y^2 <= 4],
BoxRatios -> Automatic]
答案 0 :(得分:1)
您在绘图范围的规范中只有timeToExp
call[]
和timetoExp
(小写t)。