我要R软件的代码
时间: 2024-01-26 16:03:37 浏览: 71
代码.R
好的,以下是R语言的代码实现,同样需要用到nlstools和minpack.lm库。
对于已知u的情况:
```R
library(nlstools)
# 定义回归函数
reg_func <- function(t, b0, b1, u) {
return (1 / (1/u + b0 * b1^t))
}
# 定义ln(y/(1-y))函数
ln_func <- function(t, b0, b1, ln_u) {
return (log(1 / exp(ln_u)) + b0 + log(b1^t))
}
# 读入数据
t <- c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
y <- c(7.5, 9.8, 11.4, 13.3, 17.2, 20.6, 29.1, 34.6, 47.4, 5)
# 对数几率转换
ln_y <- log(y / (1 - y))
# 线性化回归
popt_ln <- nls.lm(ln_y ~ ln_func(t, b0, b1, ln_u),
start = list(b0 = 1, b1 = 0.5, ln_u = log(100)))
# 提取参数
b0_ln <- coef(popt_ln)[1]
b1_ln <- coef(popt_ln)[2]
ln_u <- coef(popt_ln)[3]
# 计算回归系数
b0 <- exp(b0_ln)
b1 <- exp(log(b1_ln))
# 输出结果
cat("u = ", exp(ln_u), "\n")
cat("b0 = ", b0, "\n")
cat("b1 = ", b1, "\n")
```
对于未知u的情况:
```R
library(minpack.lm)
# 定义回归函数
reg_func <- function(t, b0, b1, u) {
return (1 / (1/u + b0 * b1^t))
}
# 读入数据
t <- c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
y <- c(7.5, 9.8, 11.4, 13.3, 17.2, 20.6, 29.1, 34.6, 47.4, 5)
# 定义拟合函数
fit_func <- function(par, t) {
return (reg_func(t, par[1], par[2], exp(par[3])))
}
# 非线性回归
popt <- nls.lm(y ~ fit_func(c(1, 0.5, log(100)), t),
start = c(1, 0.5, log(100)),
lower = c(0, 0, -Inf),
upper = c(Inf, 1, Inf))
# 提取参数
b0 <- coef(popt)[1]
b1 <- coef(popt)[2]
u <- exp(coef(popt)[3])
# 输出结果
cat("u = ", u, "\n")
cat("b0 = ", b0, "\n")
cat("b1 = ", b1, "\n")
```
希望这些代码能够帮助到你。
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