在R中的图上画一条对数曲线
我有以下一组数据,绘制时有一个曲线关系在R中的图上画一条对数曲线,r,ggplot2,regression,curve-fitting,R,Ggplot2,Regression,Curve Fitting,我有以下一组数据,绘制时有一个曲线关系 Fish.species.richness Habitat.Complexity log.habitat 17 0.6376 -0.1954858 13 0.2335 -0.6317131 30 0.2866 -0.5427238 20 0.3231 -0.4906630 22 0.1073 -0.9694003 25 0.2818 -0.5500590 2 0.2182 -0.6612448 4 0.0189 -
Fish.species.richness Habitat.Complexity log.habitat
17 0.6376 -0.1954858
13 0.2335 -0.6317131
30 0.2866 -0.5427238
20 0.3231 -0.4906630
22 0.1073 -0.9694003
25 0.2818 -0.5500590
2 0.2182 -0.6612448
4 0.0189 -1.7246886
19 0.2960 -0.5287083
25 0.5507 -0.2590849
29 0.2689 -0.5704900
21 0.6286 -0.2016602
18 0.1557 -0.8078509
24 0.6851 -0.1642460
30 0.5059 -0.2959353
32 0.4434 -0.3532043
29 0.3585 -0.4455108
32 0.5920 -0.2276783
当我记录x轴并进行线性回归以找到截距和斜率时,我能够添加一条适合数据的直线:
summary(lm(Fish.species.richness~log.habitat,data=three))
plot(three$log.habitat,
three$Fish.species.richness,
xlab='Log Habitat Complexity',
ylab='Fish Species Richness')
abline(29.178,13.843)
然而,当我做一个曲线回归,并试图绘制曲线,它不符合数据,我会错在哪里
mod.log<-lm(Fish.species.richness~log(Habitat.Complexity),data=three)
plot(three$Habitat.Complexity,
three$Fish.species.richness)
abline(mod.log)
mod.logabline
只能以y=a+bx的形式绘制直线。可以使用曲线
功能添加其他曲线
plot(Fish.species.richness ~ Habitat.Complexity, three)
curve(coef(mod.log)[1] + coef(mod.log)[2]*log(x), add=TRUE)
为使其他模型类型更清晰、更灵活,您可能希望使用predict
功能沿预测变量范围计算预测值:
mod.log<-lm(Fish.species.richness~log(Habitat.Complexity), data=three)
# predict along predictor variable range
newdat <- data.frame(Habitat.Complexity=seq(min(three$Habitat.Complexity), max(three$Habitat.Complexity),,100))
newdat$Fish.species.richness <- predict(mod.log, newdat, type="response")
# plot
plot(Fish.species.richness ~ Habitat.Complexity, data=three)
lines(Fish.species.richness ~ Habitat.Complexity, data=newdat)
mod.log使用ggplot2
:
ggplot(three, aes(Habitat.Complexity, Fish.species.richness))+
geom_point(shape = 1) + stat_smooth(method = "lm", formula = y ~ log(x))