我正在尝试在我的数据集中使用R中的glm（）命令（data_2，见下文）。我使用以下命令：
glm(formula = GRM_KerkMeerlo ~ ((fGS*0.865 + fQS*EC_QS + fXS*EC_fXS)/Q), data = data_2)
我认为我做的是正确的，但当我运行此输入时，我收到错误：
terms.formula（formula，data = data）中的错误：ExtractVars中的模型公式无效
我已经浏览了这个网站以找出我做错了但没有结果，所以我在这里，问我在地球上做错了什么。
我认为我犯了一个可以轻易解决的错误，我只是看不出来。
谢谢！
data_2
date P ETpot Q T fXS GRM_KerkMeerlo GRM_SintJorisweg fGS
fQS
1 2016032400 0 0.000 0.00816 4.0 0.00431 0.49775 0.45550 NA NA
2 2016032401 0 0.000 0.00814 4.6 0.00431 0.49675 0.45675 0.0022 0.0022
3 2016032402 0 0.000 0.00816 5.2 0.00431 0.49725 0.45600 0.0022 0.0021
4 2016032403 0 0.000 0.00812 5.3 0.00431 0.49600 0.45625 0.0021 0.0021
5 2016032404 0 0.000 0.00809 5.5 0.00431 0.49550 0.45525 0.0021 0.0020
6 2016032405 0 0.001 0.00812 6.5 0.00431 0.49525 0.45425 0.0021 0.0020
7 2016032406 0 0.009 0.00807 6.9 0.00431 0.49575 0.45550 0.0021 0.0019
8 2016032407 0 0.018 0.00803 7.0 0.00431 0.49600 0.45400 0.0021 0.0019
9 2016032408 0 0.032 0.00801 7.4 0.00431 0.49700 0.45175 0.0021 0.0019
10 2016032409 0 0.060 0.00801 8.3 0.00431 0.49800 0.45050 0.0021 0.0018
11 2016032410 0 0.066 0.00788 8.7 0.00431 0.49825 0.45100 0.0021 0.0018
12 2016032411 0 0.088 0.00799 9.5 0.00431 0.49850 0.45075 0.0021 0.0018
13 2016032412 0 0.102 0.00797 9.6 0.00431 0.50200 0.45025 0.0021 0.0017
14 2016032413 0 0.077 0.00805 9.9 0.00431 0.50150 0.45000 0.0021 0.0017
15 2016032414 0 0.074 0.00801 9.9 0.00431 0.50075 0.44775 0.0021 0.0017
16 2016032415 0 0.053 0.00803 9.7 0.00431 0.50150 0.44825 0.0021 0.0016
17 2016032416 0 0.018 0.00799 9.4 0.00431 0.50050 0.44725 0.0021 0.0016
18 2016032417 0 0.003 0.00803 8.8 0.00431 0.49975 0.45000 0.0021 0.0016
19 2016032418 0 0.000 0.00793 8.1 0.00431 0.49925 0.45025 0.0021 0.0015
20 2016032419 0 0.000 0.00791 8.1 0.00431 0.49825 0.44600 0.0021 0.0015
21 2016032420 0 0.000 0.00797 8.1 0.00431 0.49875 0.44475 0.0021 0.0015
22 2016032421 0 0.000 0.00791 7.3 0.00431 0.50100 0.44300 0.0021 0.0014
23 2016032422 0 0.000 0.00784 7.0 0.00431 0.50100 0.44125 0.0021 0.0014
24 2016032423 0 0.000 0.00795 7.6 0.00431 0.50050 0.44050 0.0021 0.0014
25 2016032500 0 0.000 0.00791 7.6 0.00374 0.50075 0.43975 0.0021 0.0013
答案 0 :(得分：2)
就像@joran在评论中所说的那样，你正在尝试对公式中的变量进行算术运算。虽然在输入公式之前对变量进行算术可能更合乎需要，但可以使用I函数在公式内执行计算，“ I 禁止解释运算符如“+”，“ - ”，“/”，“^”作为公式运算符“（?I）：
mod = glm(formula = GRM_KerkMeerlo ~ I((fGS*0.865 + fQS*fXS)/Q), data = df)
<强>结果：
> summary(mod)
Call:
glm(formula = GRM_KerkMeerlo ~ I((fGS * 0.865 + fQS * fXS)/Q),
data = df)
Deviance Residuals:
Min 1Q Median 3Q Max
-0.0030453 -0.0021617 -0.0000753 0.0017784 0.0032462
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 0.45976 0.03871 11.877 4.85e-11 ***
I((fGS * 0.865 + fQS * fXS)/Q) 0.17041 0.16921 1.007 0.325
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
(Dispersion parameter for gaussian family taken to be 4.71708e-06)
Null deviance: 0.00010856 on 23 degrees of freedom
Residual deviance: 0.00010378 on 22 degrees of freedom
(1 observation deleted due to missingness)
AIC: -222.32
Number of Fisher Scoring iterations: 2
请注意，我更改了您的公式以用于演示目的，因为未提供EC_QS和EC_fXS。
数据：
df = structure(list(date = c(2016032400L, 2016032401L, 2016032402L,
2016032403L, 2016032404L, 2016032405L, 2016032406L, 2016032407L,
2016032408L, 2016032409L, 2016032410L, 2016032411L, 2016032412L,
2016032413L, 2016032414L, 2016032415L, 2016032416L, 2016032417L,
2016032418L, 2016032419L, 2016032420L, 2016032421L, 2016032422L,
2016032423L, 2016032500L), P = c(0L, 0L, 0L, 0L, 0L, 0L, 0L,
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L,
0L, 0L), ETpot = c(0, 0, 0, 0, 0, 0.001, 0.009, 0.018, 0.032,
0.06, 0.066, 0.088, 0.102, 0.077, 0.074, 0.053, 0.018, 0.003,
0, 0, 0, 0, 0, 0, 0), Q = c(0.00816, 0.00814, 0.00816, 0.00812,
0.00809, 0.00812, 0.00807, 0.00803, 0.00801, 0.00801, 0.00788,
0.00799, 0.00797, 0.00805, 0.00801, 0.00803, 0.00799, 0.00803,
0.00793, 0.00791, 0.00797, 0.00791, 0.00784, 0.00795, 0.00791
), T = c(4, 4.6, 5.2, 5.3, 5.5, 6.5, 6.9, 7, 7.4, 8.3, 8.7, 9.5,
9.6, 9.9, 9.9, 9.7, 9.4, 8.8, 8.1, 8.1, 8.1, 7.3, 7, 7.6, 7.6
), fXS = c(0.00431, 0.00431, 0.00431, 0.00431, 0.00431, 0.00431,
0.00431, 0.00431, 0.00431, 0.00431, 0.00431, 0.00431, 0.00431,
0.00431, 0.00431, 0.00431, 0.00431, 0.00431, 0.00431, 0.00431,
0.00431, 0.00431, 0.00431, 0.00431, 0.00374), GRM_KerkMeerlo = c(0.49775,
0.49675, 0.49725, 0.496, 0.4955, 0.49525, 0.49575, 0.496, 0.497,
0.498, 0.49825, 0.4985, 0.502, 0.5015, 0.50075, 0.5015, 0.5005,
0.49975, 0.49925, 0.49825, 0.49875, 0.501, 0.501, 0.5005, 0.50075
), GRM_SintJorisweg = c(0.4555, 0.45675, 0.456, 0.45625, 0.45525,
0.45425, 0.4555, 0.454, 0.45175, 0.4505, 0.451, 0.45075, 0.45025,
0.45, 0.44775, 0.44825, 0.44725, 0.45, 0.45025, 0.446, 0.44475,
0.443, 0.44125, 0.4405, 0.43975), fGS = c(NA, 0.0022, 0.0022,
0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021,
0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021,
0.0021, 0.0021, 0.0021, 0.0021, 0.0021, 0.0021), fQS = c(NA,
0.0022, 0.0021, 0.0021, 0.002, 0.002, 0.0019, 0.0019, 0.0019,
0.0018, 0.0018, 0.0018, 0.0017, 0.0017, 0.0017, 0.0016, 0.0016,
0.0016, 0.0015, 0.0015, 0.0015, 0.0014, 0.0014, 0.0014, 0.0013
)), .Names = c("date", "P", "ETpot", "Q", "T", "fXS", "GRM_KerkMeerlo",
"GRM_SintJorisweg", "fGS", "fQS"), class = "data.frame", row.names = c("1",
"2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13",
"14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24",
"25"))