如何在 R 中传递公式作为参数?
下面的代码适用于前两种情况,但是当我传入公式时,出现错误: Error in model.frame.default(formula = formula, weights = weights, na.action = na.omit, : invalid type (closure) for variable '(weights)'
makeModel<-function(formula,weights) {
m <- lm(formula, na.action = na.omit, weights = weights)
return(m);
}
run<-function(t) {
f<-formula(t$y~t$x+t$r)
m <- lm(t$y~t$x+t$r, na.action = na.omit, weights = t$size)
m <- lm(f, na.action = na.omit, weights = t$size)
m <- makeModels(f,t$size)
}
l<-20
x<-seq(0,1,1/l)
y<-sqrt(x)
r=round(runif(n=length(x),min=0,max=.8))
n<-1:(l+1)
size=n/sum(n)
t<-data.frame(x,y,r,n,size)
run(t)
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编辑1:这段代码:
makeModel<-function(formula,weights,t) {
print(class(weights))
m <- lm(formula, na.action = na.omit, weights = weights,data=t)
return(m);
}
run<-function(t) {
f<-formula(y~x+r)
f <- as.formula("t$y~t$x+t$r")
m <- lm(y~x+r, na.action = na.omit, weights = t$size,data=t)
m <- lm(f, na.action = na.omit, weights = t$size,data=t)
m <- makeModel(f,t$size,t)
}
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产生:
model.frame.default 中的错误(公式 = 公式,数据 = t,权重 = 权重,:变量“(权重)”的类型(闭包)无效
编辑2:作品:
makeModel <- function(formula, data) {
# size is looked in data first, which is why this works
m <- lm(formula, na.action = na.omit, weights = size, data = data) # works
#m <- lm(formula, na.action = na.omit, weights = data$size, data = data) # fails!
return(m)
}
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r 很奇怪!
有谁知道为什么以下行:weights=data$size 失败?
编辑3:得到:weights=data$size 可以工作。
makeModel<-function(formula,w,data) {
print(class(weights))
m <- lm(formula, na.action = na.omit, weights = size, data = data) # works
m <- lm(formula, na.action = na.omit, weights = data$size, data = data) #works
m <- lm(formula, na.action = na.omit, weights = w,data=data) # fails
return(m);
}
run<-function(data) {
f<-formula(y~x+r)
#f <- as.formula("t$y~t$x+t$r")
m <- lm(y~x+r, na.action = na.omit, weights = data$size,data=data)
m <- lm(f, na.action = na.omit, weights = data$size,data=data)
m <- makeModel(f,data$size,data)
}
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最后一个失败并显示: eval(extras, data, env) 中的错误:找不到对象“w”
请参阅 中的示例?as.formula。您不应该从变量名称中显式调用变量。该公式应该是一个抽象的,并且lm知道要从中提取哪些变量data,您应该指定哪些变量。
makeModels <- function(formula, data) {
# size is looked in data first, which is why this works
m <- lm(formula, na.action = na.omit, weights = size, data = data)
return(m)
}
run <- function(t) {
f <- formula(y ~ x + r)
m1 <- lm(formula = f, na.action = na.omit, weights = size, data = t)
m2 <- makeModels(formula = f, data = t)
return(list(m1, m2))
}
l<-20
x<-seq(0,1,1/l)
y<-sqrt(x)
r=round(runif(n = length(x), min = 0, max = 0.8))
n<-1:(l+1)
size=n/sum(n)
t<-data.frame(x,y,r,n,size)
run(t)
[[1]]
Call:
lm(formula = f, data = t, weights = t$size, na.action = na.omit)
Coefficients:
(Intercept) x r
0.327154 0.706553 -0.008167
[[2]]
Call:
lm(formula = formula, data = data, weights = size, na.action = na.omit)
Coefficients:
(Intercept) x r
0.327154 0.706553 -0.008167
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