在geom_smooth中使用`nlsfit`以添加指數線來繪制

Question

我想nlsfit將easynls 包中的easynls與ggplot2一起使用。

到目前為止，這是我所做的：

1. 設置子集數據：

    library('ggplot2') library('easynls') x <- seq(25,97) y <- c(0.014, 0.016, 0.015, 0.016, 0.018, 0.019, 0.023, 0.019, 0.021, 0.017, 0.018, 0.016, 0.016, 0.020, 0.018, 0.019, 0.022, 0.023, 0.027, 0.027, 0.028, 0.031, 0.029, 0.032, 0.030, 0.030, 0.030, 0.033, 0.039, 0.038, 0.039, 0.046, 0.042, 0.043, 0.050, 0.054, 0.059, 0.064, 0.062, 0.058, 0.063, 0.069, 0.071, 0.069, 0.073, 0.071, 0.070, 0.077, 0.086, 0.077, 0.090, 0.086, 0.098, 0.108, 0.112, 0.116, 0.129, 0.120, 0.128, 0.141, 0.150, 0.143, 0.148, 0.150, 0.162, 0.162, 0.168, 0.152, 0.151, 0.161, 0.169, 0.189, 0.184) data <- data.frame(x,y) 

2. 對樣本數據運行NLSfit

    nlsfit = nlsfit(data.frame(x,y), model=6, start=c(250,0.05)) nlsfit # $Model # [1] "y~a*exp(b*x)" # $Parameters # y # coefficient a 0.0061 # coefficient b 0.0358 # p-value t.test for a 0.0000 # p-value t.test for b 0.0000 # r-squared 0.9793 # adjusted r-squared 0.9790 # AIC -500.0812 # BIC -493.2098 

3. 使用plot()一條線

    plot(x, y) a <- nlsfit$Parameters[1,] b <- nlsfit$Parameters[2,] lines(x, a*exp(x*b), col="steelblue") 

4. 嘗試將nls與ggplot2一起使用（此方法有效-但是在整個數據集上擬合度並不理想）...

    ggplot(data, aes(x=x, y=y)) + geom_point( ) + geom_smooth(method="nls", formula=y~a*exp(x*b), method.args=list(start=c(a=250,b=0.05)), se=FALSE) 

5. 嘗試使用nlsfit進行nlsfit-不起作用

    # Below doesn't work ggplot(data, aes(x=x, y=y)) + geom_point( ) + geom_smooth(method="nlsfit", formula=y~a*exp(x*b), method.args=list(data.frame(x, y), model=6, start=c(250,0.05)), se=FALSE) # Warning message: # Computation failed in `stat_smooth()`: # unused arguments (formula, weights = weight, list(x = 25:97, y = c(0.014, 0.016, 0.015, 0.016, 0.018, 0.019, 0.023, 0.019, 0.021, 0.017, 0.018, 0.016, 0.016, 0.02, 0.018, 0.019, 0.022, 0.023, 0.027, 0.027, 0.028, 0.031, 0.029, 0.032, 0.03, 0.03, 0.03, 0.033, 0.039, 0.038, 0.039, 0.046, 0.042, 0.043, 0.05, 0.054, 0.059, 0.064, 0.062, 0.058, 0.063, 0.069, 0.071, 0.069, 0.073, 0.071, 0.07, 0.077, 0.086, 0.077, 0.09, 0.086, 0.098, 0.108, 0.112, 0.116, 0.129, 0.12, 0.128, 0.141, 0.15, 0.143, 0.148, 0.15, 0.162, # 0.162, 0.168, 0.152, 0.151, 0.161, 0.169, 0.189, 0.184))) 

這可能嗎？將不勝感激。 謝謝。

Answer 1

您可以嘗試使用stat_function使最后一部分起作用：

a <- nlsfit$Parameters[row.names(nlsfit$Parameters) == 'coefficient a',]
b <- nlsfit$Parameters[row.names(nlsfit$Parameters) == 'coefficient b',]
ggplot(data, aes(x=x, y=y)) + geom_point() + 
  stat_function(fun=function(x) a*exp(b*x), colour = "blue")