Question

我遇到了与ggplot2奇怪的事情。我有一个生成barplots的循环脚本，并将它们中的每一个保存为tiff文件。我不希望条形之间有任何间距，我认为我已正确编写脚本来做到这一点，但我的一些图表显示了条形图和一些条形图之间的发线。因为它是一个循环，所以它们的脚本和数据结构完全相同。这是一个可重复的例子：

 require(gridExtra); require(ggplot2); require(grid)
 prod.data1 = structure(list(date.time = structure(c(1465362000, 1465365600, 
    1465369200, 1465372800, 1465376400, 1465380000, 1465383600, 1465387200, 
    1465390800, 1465394400, 1465398000, 1465401600, 1465405200, 1465408800, 
    1465412400, 1465416000, 1465419600, 1465423200, 1465426800, 1465430400, 
    1465434000, 1465437600, 1465441200, 1465444800, 1465448400, 1465452000, 
    1465455600, 1465459200, 1465462800, 1465466400, 1465470000, 1465473600, 
    1465477200, 1465480800, 1465484400, 1465488000, 1465491600, 1465495200, 
    1465498800, 1465502400, 1465506000, 1465509600, 1465513200, 1465516800, 
    1465520400, 1465524000, 1465527600, 1465531200, 1465534800, 1465538400, 
    1465542000, 1465545600, 1465549200, 1465552800, 1465556400, 1465560000, 
    1465563600, 1465567200, 1465570800, 1465574400, 1465578000, 1465581600, 
    1465585200, 1465588800, 1465592400, 1465596000, 1465599600, 1465603200, 
    1465606800, 1465610400, 1465614000, 1465617600, 1465621200, 1465624800, 
    1465628400, 1465632000, 1465635600, 1465639200, 1465642800, 1465646400, 
    1465650000, 1465653600, 1465657200, 1465660800, 1465664400, 1465668000, 
    1465671600, 1465675200, 1465678800, 1465682400, 1465686000, 1465689600, 
    1465693200, 1465696800, 1465700400, 1465704000, 1465707600, 1465711200, 
    1465714800, 1465718400, 1465722000, 1465725600, 1465729200, 1465732800, 
    1465736400, 1465740000, 1465743600, 1465747200, 1465750800, 1465754400, 
    1465758000, 1465761600, 1465765200, 1465768800, 1465772400, 1465776000, 
    1465779600, 1465783200, 1465786800, 1465790400, 1465794000, 1465797600, 
    1465801200, 1465804800, 1465808400, 1465812000, 1465815600, 1465819200, 
    1465822800, 1465826400, 1465830000, 1465833600, 1465837200, 1465840800, 
    1465844400, 1465848000, 1465851600, 1465855200, 1465858800, 1465862400, 
    1465866000, 1465869600, 1465873200, 1465876800, 1465880400, 1465884000, 
    1465887600, 1465891200, 1465894800, 1465898400, 1465902000, 1465905600, 
    1465909200, 1465912800, 1465916400, 1465920000, 1465923600, 1465927200, 
    1465930800, 1465934400, 1465938000, 1465941600, 1465945200, 1465948800, 
    1465952400, 1465956000, 1465959600, 1465963200, 1465966800, 1465970400, 
    1465974000, 1465977600, 1465981200, 1465984800, 1465988400, 1465992000, 
    1465995600, 1465999200, 1466002800, 1466006400, 1466010000, 1466013600, 
    1466017200, 1466020800, 1466024400, 1466028000, 1466031600, 1466035200, 
    1466038800, 1466042400, 1466046000, 1466049600, 1466053200, 1466056800, 
    1466060400, 1466064000, 1466067600, 1466071200, 1466074800, 1466078400, 
    1466082000, 1466085600, 1466089200, 1466092800, 1466096400, 1466100000, 
    1466103600, 1466107200, 1466110800, 1466114400, 1466118000, 1466121600, 
    1466125200, 1466128800, 1466132400, 1466136000), class = c("POSIXct", 
    "POSIXt")), production = c(5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 9.9, 
    9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 13.4, 13.4, 13.4, 13.4, 
    13.4, 13.4, 9.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 9.9, 
    9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 13.4, 13.4, 13.4, 13.4, 
    13.4, 13.4, 9.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 9.9, 
    9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 13.4, 13.4, 13.4, 13.4, 
    13.4, 13.4, 9.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 5.9, 9.9, 
    9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 9.9, 13.4, 13.4, 13.4, 13.4, 
    13.4, 13.4, 9.9, 5.9, 5.9, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 7.1, 
    7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 
    7.1, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 7.1, 7.1, 7.1, 
    7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 3.1, 
    3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 7.1, 7.1, 7.1, 7.1, 7.1, 
    7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 3.1, 3.1, 3.1, 
    3.1, 3.1, 3.1, 3.1, 3.1, 3.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 
    7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 3.1, 3.1, 3.1, 3.1, 3.1, 
    3.1, 3.1, 3.1, 3.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 
    7.1, 7.1, 7.1, 7.1, 7.1, 7.1, 3.1, 3.1, 3.1), ID = structure(c(15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 15L, 
    15L, 15L, 15L, 15L, 15L, 15L, 15L), .Label = c("A", "B", "C","D", 
    "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P"), 
    class = "factor"), ILP = c(10.72, 
    8.66, 7.75, 7.25, 7.91, 9.12, 10.33, 12.93, 15.7, 15.72, 16.7, 
    15.34, 14.6, 14.34, 13.09, 11.52, 12.08, 13.29, 14.56, 13.74, 
    15.46, 15.37, 12.49, 11.11, 7.78, 5.92, 5.92, 5.91, 6.11, 7.01, 
    10.05, 10.49, 11.43, 11.45, 12.21, 12.79, 12.09, 11.94, 11.99, 
    10.87, 11.31, 12.08, 13.33, 13.31, 14.23, 13.01, 10.84, 10.07, 
    7.08, 5.04, 5.01, 5.06, 5.22, 6, 9.92, 10.74, 12.53, 12.43, 13.34, 
    13.24, 13.52, 12.95, 13.86, 13.09, 13.79, 12.44, 14.14, 14.05, 
    14.36, 14.45, 11.66, 10.4, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667, 11.3366666666667, 11.3366666666667, 
    11.3366666666667, 11.3366666666667), Class = structure(c(2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 4L, 4L, 4L, 3L, 3L, 3L, 3L, 2L, 2L, 3L, 
    3L, 3L, 4L, 3L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 
    3L, 3L, 3L, 3L, 3L, 2L, 2L, 3L, 4L, 4L, 4L, 4L, 2L, 2L, 2L, 2L, 
    2L, 2L, 2L, 2L, 2L, 2L, 3L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 
    4L, 4L, 4L, 4L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
    1L, 1L, 1L, 1L, 1L, 1L), .Label = c("NA", "Low", "Medium", 
    "High"), class = "factor")), .Names = c("date.time", "production", 
    "ID", "ILP", "Class"), row.names = 3025:3240, class = "data.frame")

prod.data2 = structure(list(date.time = structure(c(1465362000, 1465365600, 
1465369200, 1465372800, 1465376400, 1465380000, 1465383600, 1465387200, 
1465390800, 1465394400, 1465398000, 1465401600, 1465405200, 1465408800, 
1465412400, 1465416000, 1465419600, 1465423200, 1465426800, 1465430400, 
1465434000, 1465437600, 1465441200, 1465444800, 1465448400, 1465452000, 
1465455600, 1465459200, 1465462800, 1465466400, 1465470000, 1465473600, 
1465477200, 1465480800, 1465484400, 1465488000, 1465491600, 1465495200, 
1465498800, 1465502400, 1465506000, 1465509600, 1465513200, 1465516800, 
1465520400, 1465524000, 1465527600, 1465531200, 1465534800, 1465538400, 
1465542000, 1465545600, 1465549200, 1465552800, 1465556400, 1465560000, 
1465563600, 1465567200, 1465570800, 1465574400, 1465578000, 1465581600, 
1465585200, 1465588800, 1465592400, 1465596000, 1465599600, 1465603200, 
1465606800, 1465610400, 1465614000, 1465617600, 1465621200, 1465624800, 
1465628400, 1465632000, 1465635600, 1465639200, 1465642800, 1465646400, 
1465650000, 1465653600, 1465657200, 1465660800, 1465664400, 1465668000, 
1465671600, 1465675200, 1465678800, 1465682400, 1465686000, 1465689600, 
1465693200, 1465696800, 1465700400, 1465704000, 1465707600, 1465711200, 
1465714800, 1465718400, 1465722000, 1465725600, 1465729200, 1465732800, 
1465736400, 1465740000, 1465743600, 1465747200, 1465750800, 1465754400, 
1465758000, 1465761600, 1465765200, 1465768800, 1465772400, 1465776000, 
1465779600, 1465783200, 1465786800, 1465790400, 1465794000, 1465797600, 
1465801200, 1465804800, 1465808400, 1465812000, 1465815600, 1465819200, 
1465822800, 1465826400, 1465830000, 1465833600, 1465837200, 1465840800, 
1465844400, 1465848000, 1465851600, 1465855200, 1465858800, 1465862400, 
1465866000, 1465869600, 1465873200, 1465876800, 1465880400, 1465884000, 
1465887600, 1465891200, 1465894800, 1465898400, 1465902000, 1465905600, 
1465909200, 1465912800, 1465916400, 1465920000, 1465923600, 1465927200, 
1465930800, 1465934400, 1465938000, 1465941600, 1465945200, 1465948800, 
1465952400, 1465956000, 1465959600, 1465963200, 1465966800, 1465970400, 
1465974000, 1465977600, 1465981200, 1465984800, 1465988400, 1465992000, 
1465995600, 1465999200, 1466002800, 1466006400, 1466010000, 1466013600, 
1466017200, 1466020800, 1466024400, 1466028000, 1466031600, 1466035200, 
1466038800, 1466042400, 1466046000, 1466049600, 1466053200, 1466056800, 
1466060400, 1466064000, 1466067600, 1466071200, 1466074800, 1466078400, 
1466082000, 1466085600, 1466089200, 1466092800, 1466096400, 1466100000, 
1466103600, 1466107200, 1466110800, 1466114400, 1466118000, 1466121600, 
1466125200, 1466128800, 1466132400, 1466136000), class = c("POSIXct", 
"POSIXt")), production = c(17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 
17.9, 17.9, 17.9, 17.9, 17.9, 65.4, 75.7, 89.2, 59.2, 49.2, 17.9, 
17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 23.2, 23.2, 23.2, 23.2, 
23.2, 23.2, 23.2, 23.2, 23.2, 23.2, 23.2, 70.7, 71.7, 98.7, 72.7, 
71.7, 23.2, 23.2, 23.2, 23.2, 23.2, 23.2, 23.2, 23.2, 24.2, 24.2, 
24.2, 24.2, 24.2, 24.2, 24.2, 24.2, 24.2, 24.2, 24.2, 71.7, 72.2, 
97.7, 76.7, 76.7, 32.2, 24.7, 24.2, 24.2, 24.2, 24.2, 24.2, 24.2, 
24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 66.2, 
66.2, 67.2, 101.7, 101.7, 101.7, 60.2, 60.2, 25.7, 24.7, 24.7, 
24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 24.7, 
24.7, 24.7, 66.2, 66.2, 67.2, 98.7, 98.7, 98.7, 57.2, 25.7, 24.7, 
24.7, 24.7, 24.7, 24.7, 24.7, 20.7, 20.7, 20.7, 20.7, 20.7, 20.7, 
20.7, 20.7, 20.7, 20.7, 62.2, 62.2, 21.2, 56.2, 21.2, 20.7, 20.7, 
20.7, 20.7, 20.7, 20.7, 20.7, 20.7, 20.7, 19.7, 19.7, 19.7, 19.7, 
19.7, 19.7, 19.7, 19.7, 19.7, 19.7, 19.7, 61.2, 64.7, 43.2, 41.2, 
28.2, 23.2, 19.7, 19.7, 19.7, 19.7, 19.7, 19.7, 19.7, 17.9, 17.9, 
17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 59.4, 64.7, 
32.2, 56.2, 32.2, 23.2, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 
17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 17.9, 
59.4, 64.7, 73.7, 56.2, 32.2, 23.2, 17.9, 17.9, 17.9, 17.9, 17.9, 
17.9, 17.9), ID = structure(c(4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L
), .Label = c("A", "B", "C","D", "E", "F", "G", "H", "I", "J", 
"K", "L", "M", "N", "O", "P"), class = "factor"), ILP = c(19.8, 19.06, 14.88, 
13.28, 12.3, 13.2, 18.95, 21.19, 21.37, 25, 25.75, 25.57, 25.19, 
23.31, 23.4, 22.69, 25.37, 24.96, 22.53, 20.54, 22.21, 20.26, 
18.94, 16.29, 16.89, 14.21, 12.72, 11.18, 10.26, 11.69, 15.95, 
18.23, 19.11, 19.78, 20.35, 20.15, 21.17, 22.45, 23.7, 24.04, 
25.58, 25.35, 21.73, 19.81, 20.77, 21.05, 20.58, 17.48, 16.09, 
14.15, 11.13, 10.14, 9.76, 11.16, 14.29, 18.79, 18.99, 19.45, 
19.52, 19.45, 20.38, 20.15, 21.52, 20.2, 20.96, 20.56, 18.42, 
17.33, 17.31, 16.95, 18.92, 15.59, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444, 18.9094444444444, 18.9094444444444, 
18.9094444444444, 18.9094444444444), Class = structure(c(2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 4L, 4L, 4L, 3L, 3L, 3L, 4L, 3L, 
3L, 2L, 3L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 3L, 2L, 3L, 3L, 3L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 4L, 3L, 4L, 3L, 4L, 4L, 
2L, 2L, 2L, 2L, 3L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L), .Label = c("NA", "Low", "Medium", 
"High"), class = "factor")), .Names = c("date.time", "production", 
"ID", "ILP", "Class"), row.names = 649:864, class = "data.frame")

prod.data.list = list(prod.data1,prod.data2)

ID = c('D','O')
for(i in 1:length(ID)) {
prod.data = prod.data.list[[i]]
 s=     ggplot(prod.data, aes(x=date.time, y= production, fill = Class),binwidth=0) +
            geom_bar(stat = 'identity')+
            scale_fill_manual(values=c("#A8A8A8","#CCFF99", "#FFA31A", "#CC2900")) +
            scale_x_datetime()  +
            theme(legend.position = c(0.06,0.82), legend.key.height=unit(0.5,"line"),legend.key.width=unit(0.3,"line"),legend.background = element_blank(),legend.title = element_text("Class",size=8)) 


        f=  ggplot(prod.data, aes(x=date.time, y=ILP))  +
            geom_line() +
            geom_point() +
            scale_x_datetime()  

tiff(filename = paste0("Prod_Price_",as.Date(now()),ID[i],".tiff"), width=7,height=4.5,units="in", pointsize=12, bg = "white", res = 150, restoreConsole = TRUE)
        gs <- ggplotGrob(s)
        gf<- ggplotGrob(f)
        grid::grid.draw(rbind(gf, gs))
        dev.off()
    }

这是我得到的一个例子（20个中的两个图表），任何想法为什么我在第二张图上的条形之间得到发线空间？为什么这种模式如此规律？谢谢你的帮助！

First example

Second example

Answer 1

请注意，binwidth不再适用于geom_bar。来自文档：

geom_bar不再具有binwidth参数 - 如果您使用它，您将获得警告告诉你使用geom_histogram。

您设法在binwidth而不是ggplot中使用geom_bar来避免警告，这使得很难意识到它实际上并没有做任何事情。

在geom_bar中使用width来更改条形的宽度。使用因子时，您可以使用width = 1（如您问题的评论中所述）来获得它们之间没有空格的条形图。使用scale_*_datetime时，情况会有所不同。

根据this answer，结果是日期时间刻度以秒为单位，因此width = 1相当于1秒的条形宽度。要在数据中获得1小时的条形宽度，您需要宽度为3600。

使用它可以消除您在第一个示例数据集中看到的空格。

ggplot(prod.data1, aes(x=date.time, y= production, fill = Class)) +
    geom_bar(stat = 'identity', width = 3600)+
    scale_fill_manual(values=c("#A8A8A8","#CCFF99", "#FFA31A", "#CC2900")) +
    scale_x_datetime()

Answer 2

您的问题与屏幕和绘图分辨率的某种组合有关。你的情节实际上在每个条形图之间都有细线，但是有限的屏幕和/或绘图分辨率会导致某些空间出现而有些空间不出现。

以下是使用样本数据创建的两个图。我已经使用grid.arrange来布局它们并将它们保存到一个对象中。我删除了主题声明，因为我在尝试运行它时遇到了错误，但这对你遇到的问题无关紧要（注意，binwidth=0没有效果，但我已经离开代码如下）：

pl = gridExtra::grid.arrange(
  ggplot(prod.data.list[[1]], aes(x=date.time, y= production, fill = Class),binwidth=0) +
    geom_bar(stat = 'identity')+
    scale_fill_manual(values=c("#A8A8A8","#CCFF99", "#FFA31A", "#CC2900")) +
    scale_x_datetime() + theme_bw() ,
  ggplot(prod.data.list[[2]], aes(x=date.time, y= production, fill = Class),binwidth=0) +
    geom_bar(stat = 'identity')+
    scale_fill_manual(values=c("#A8A8A8","#CCFF99", "#FFA31A", "#CC2900")) +
    scale_x_datetime() + theme_bw()
)

好的，现在让我们把它保存为PDF：

pdf("test.pdf", 8,2)
plot(pl)
dev.off()

请注意，每个栏之间都有一个空格：

现在看看保存为png的相同情节有两个分辨率：

png("test1.png", 1000,200)
plot(pl)
dev.off()

png("test2.png", 3000,600)
plot(pl)
dev.off()

正如您所看到的，第一个图以较低的分辨率显示了条形之间的一些空格，而在其他情况下，空格消失了。较高分辨率的图显示了所有空格。

要摆脱这些空格，请在width=3600中使用geom_bar（因为您的垃圾箱是1小时= 3600秒宽，POSIXct格式是以秒为单位）。

pl2 = gridExtra::grid.arrange(
  ggplot(prod.data.list[[1]], aes(x=date.time, y= production, fill = Class)) +
    geom_bar(stat = 'identity', width=3600)+
    scale_fill_manual(values=c("#A8A8A8","#CCFF99", "#FFA31A", "#CC2900")) +
    scale_x_datetime() + theme_bw() ,
  ggplot(prod.data.list[[2]], aes(x=date.time, y= production, fill = Class)) +
    geom_bar(stat = 'identity')+
    scale_fill_manual(values=c("#A8A8A8","#CCFF99", "#FFA31A", "#CC2900")) +
    scale_x_datetime() + theme_bw()
)

png("test3.png", 1000, 200)
plot(pl2)
dev.off()

png("test4.png", 3000, 600)
plot(pl2)
dev.off()

正如您在下面的每个图中所看到的，由于width的变化，条形图之间的空格现在已经在上面板中消失了。

Barplot：为什么我在ggplot2中为相同的脚本获得了条之间的可变间距？

2 个答案: