r - 警告信息说明

Question

我正在使用 SNPassoc用于查找数据 SNP 与连续变量结果之间关联的 R 包。我运行分析并得到结果；但是，我收到警告消息:

Warning in terms.formula(formula, data = data) :
  'varlist' has changed (from nvar=3) to new 4 after EncodeVars() -- should no longer happen!

我的模型是:

model <- WGassociation (continuous variable ~ covariate +covariate+ covariate  ,data= data)
model

我不知道这意味着什么，我应该担心还是忽略它？你能帮帮我吗？

Answer 1

此警告消息即将出现 glm，它由 SNPassoc::WGassociation 使用，see this line on GitHub .

警告消息说它正在删除一些变量，因为它是模型中其他现有变量的线性组合。

要重现此警告，请尝试以下示例:

# data
x <- mtcars[, 1:4]

# run model, all good
glm(mpg ~ ., data = x)
# Call:  glm(formula = mpg ~ ., data = x)
# 
# Coefficients:
#   (Intercept)          cyl         disp           hp  
# 34.18492     -1.22742     -0.01884     -0.01468  
# 
# Degrees of Freedom: 31 Total (i.e. Null);  28 Residual
# Null Deviance:        1126 
# Residual Deviance: 261.4  AIC: 168

现在添加无用的组合变量，它是从现有变量构造的。

# make a combo var
cyldisp <- x$cyl + x$disp

# run model with combo var, now we get the warning
glm(mpg ~ . + cylmpg, data = x)
# Call:  glm(formula = mpg ~ . + cyldisp, data = x)
# 
# Coefficients:
#   (Intercept)          cyl         disp           hp      cyldisp  
# 34.18492     -1.22742     -0.01884     -0.01468           NA  
# 
# Degrees of Freedom: 31 Total (i.e. Null);  28 Residual
# Null Deviance:        1126 
# Residual Deviance: 261.4  AIC: 168
# Warning message:
#   In terms.formula(formula, data = data) :
#   'varlist' has changed (from nvar=4) to new 5 after EncodeVars() -- should no longer happen!