使用R中的腳本生成pdf時出錯使用R中的腳本

Question

我使用R循環遍歷數據框的列並生成分析結果圖。腳本運行時，我不會收到任何錯誤，但會生成無法打開的pdf。

如果我運行腳本的內容，它工作正常。我想知道是否有一個問題，它循環的速度有多快，所以我試圖強迫它暫停。這似乎沒有什麼區別。我對任何人的建議都很感興趣，而且我對R也很陌生，所以我建議如何改進這種方法也值得歡迎。謝謝。

for (i in 2:22) { 

    # Organise data 
    pop_den_z = subset(pop_den, pop_den[i] != "0") # Remove zeros 
    y = pop_den_z[,i]  # Get y col 
    x = pop_den_z[,1]  # get x col 
    y = log(y)    # Log transform 

    # Regression 
    lm.0 = lm(formula = y ~ x)    # make linear model 
    inter = summary(lm.0)$coefficients[1,1] # Get intercept 
    slop = summary(lm.0)$coefficients[2,1] # Get slope 

    # Write to File 
    a = c(i, inter, slop) 
    write(a, file = "C:/pop_den_coef.txt", ncolumns = 3, append = TRUE, sep = ",") 

    ## Setup pdf 
    string = paste("C:/LEED/results/Images/R_graphs/Pop_den", paste(i-2), "City.pdf") 
    pdf(string, height = 6, width = 9) 

    p <- qplot(
    x, y, 
    xlab = "Radius [km]", 
    ylab = "Population Density [log(people/km)]", 
    xlim = x_range, 
    main = "Analysis of Cities" 
) 

    # geom_abline(intercept,slope) 
    p + geom_abline(intercept = inter, slope = slop, colour = "red", size = 1) 

    Sys.sleep(5) 

    ### close the PDF file 
    dev.off() 
} 

Answer 1

該行應該是

print(p + geom_abline(intercept = inter, slope = slop, colour = "red", size = 1)) 

在PDF設備，ggplot（和晶格）只寫明確地打印時到文件。