问题
I am trying to create a pdf page conatining 6 plots (3 rows and 2 columns) using a for loop. I am able to create the plots but i cant seem to automate adding a regression line to each plot.
I am trying the following code.
#Dummy data
Data1 <- data.frame(flow = c(8,8.5,6,7.1,9), SP_elev = c(20,11,5,25,50))
Data2 <- data.frame(flow = c(7,7.2,6.5,8.2,8.5), SP_elev = c(13,15,18,25,19))
Data3 <- data.frame(flow = c(2,3,5,7,9), SP_elev = c(20,25,28,30,35))
Data4 <- data.frame(flow = c(1,4,6,8,9), SP_elev = c(13,15,18,25,19))
Data5 <- data.frame(flow = c(1,4,6,8,9), SP_elev = c(13,15,18,25,19))
Data6 <- data.frame(flow = c(1,4,6,8,9), SP_elev = c(22,23,25,27,29))
#Create Vector list
dataframes = list("Data1" = Data1,
"Data2" = Data2,
"Data3" = Data3,
"Data4" = Data4,
"Data5" = Data5,
"Data6" = Data6) # I gave up here
# open the PDF device
pdf(file="Dummy_Example.pdf", paper="letter", height=10, width=8)
#Create array of plots
par(mfrow=c(3,2))
#plot a with regression model
for (i in dataframes) {
plot (i[,c('flow', 'SP_elev')], xlab=expression(paste("Discharge (", ft^3, "/s)",sep = "")), ylab= "Elevation (m)", tck=0.02, adj = 0.5)
#plot regression curve
fit2<-lm(i$SP_elev ~ i$flow + I(i$flow^2), data=i)
pol2 <- function(x) fit2$coefficient[3]*x^2 + fit2$coefficient[2]*x + fit2$coefficient[1]
curve(pol2, lwd=1, add=T)
}
# close the PDF device
dev.off()
I got the regression curve code to work when i am individually producing a plot but it wont seem to work when i try to automate it.
In addition I also want to plot the equation of the regression curve on the graph.
Thanks,
dubbdan
回答1:
I edited the code above to include the equation in the plot. Update: Now prettier equation.
#Dummy data
Data1 <- data.frame(flow = c(8,8.5,6,7.1,9), SP_elev = c(20,11,5,25,50))
Data2 <- data.frame(flow = c(7,7.2,6.5,8.2,8.5), SP_elev = c(13,15,18,25,19))
Data3 <- data.frame(flow = c(2,3,5,7,9), SP_elev = c(20,25,28,30,35))
Data4 <- data.frame(flow = c(1,4,6,8,9), SP_elev = c(13,15,18,25,19))
Data5 <- data.frame(flow = c(1,4,6,8,9), SP_elev = c(13,15,18,25,19))
Data6 <- data.frame(flow = c(1,4,6,8,9), SP_elev = c(22,23,25,27,29))
#Create Vector list
dataframes = list("Data1" = Data1,
"Data2" = Data2,
"Data3" = Data3,
"Data4" = Data4,
"Data5" = Data5,
"Data6" = Data6) # I gave up here
# open the PDF device
pdf(file="Dummy_Example.pdf", paper="letter", height=10, width=8)
#Create array of plots
par(mfrow=c(3,2))
#plot a with regression model
for (i in dataframes) {
plot (SP_elev ~ flow, data=i,
xlab=expression(paste("Discharge (", ft^3, "/s)",sep = "")),
ylab= "Elevation (m)", tck=0.02, adj = 0.5)
#plot regression curve
fit2<-lm(SP_elev ~ flow + I(flow^2), data=i)
pol2 <- function(x) fit2$coefficient[3]*x^2 + fit2$coefficient[2]*x + fit2$coefficient[1]
curve(pol2, lwd=1, add=T, col="blue")
xm <- min(i$flow)
ym <- max(i$SP_elev)
co <- signif(coef(fit2),3)
text(xm, ym,
bquote(y==.(co[3])*x^2 + .(co[2])*x + .(co[1])),
adj=c(0,1))
}
dev.off()
来源:https://stackoverflow.com/questions/22970708/plot-quadratic-regression-with-equation-displayed