Question

在R中，可以使用以下命令绘制回归线：

res=lm(height~age)
abline(res)

根据http://msenux.redwoods.edu/math/R/regression.php

的建议

我怎么能用rpy2做同样的事情？我试过了

from rpy2 import robjects
r = robjects.r
r.png('test.png')
x = range(10)
y = range(10)
r.plot(x, y)
r.abline(r.lm(x, y))

但被rpy2抱怨：

Error in formula.default(object, env = baseenv()) : invalid formula
Traceback (most recent call last):
  File "plot_ratio_price.py", line 34, in <module>
    r.abline(r.lm(x, y))
  File "/Library/Python/2.7/site-packages/rpy2/robjects/functions.py", line 82, in __call__
    return super(SignatureTranslatedFunction, self).__call__(*args, **kwargs)
  File "/Library/Python/2.7/site-packages/rpy2/robjects/functions.py", line 34, in __call__
    res = super(Function, self).__call__(*new_args, **new_kwargs)
rpy2.rinterface.RRuntimeError: Error in formula.default(object, env = baseenv()) : invalid formula

任何提示？谢谢！

Answer 1

继续@joran的评论后，Rpy2要求你为公式提供一个特殊的对象。文档说明了班级robjects.Formula represents an R formula。因此，在您的最后一行（对r.abline的调用）之前，您需要创建一个公式对象并将其传递到lm()来电。

顺便说一下，您的问题代码看起来足够接近您可能考虑将其用作模板的rpy2示例：

import array
from rpy2.robjects import IntVector, Formula
from rpy2.robjects.packages import importr
stats = importr('stats')

x = IntVector(range(1, 10))
y = IntVector(range(1, 10))

fmla = Formula('y ~ x')
env = fmla.environment
env['x'] = x
env['y'] = y

fit = stats.lm(fmla)

如何用rpy2绘制回归线

1 个答案: