我有每日灌溉的数据，从一年到下一年交叉：
df <- structure(list(date = structure(c(4261, 4262, 4263, 4264, 4265,
4266, 4267, 4268, 4269, 4270, 4271, 4272, 4273, 4274, 4275, 4276,
4277, 4278, 4279, 4280, 4281, 4282, 4283, 4284, 4285, 4286, 4287,
4288, 4289, 4290, 4291, 4292, 4293, 4294, 4295, 4296, 4297, 4298,
4299, 4300, 4301, 4302, 4303, 4304, 4305, 4306, 4307, 4308, 4309,
4310, 4311, 4312, 4313, 4314, 4315, 4316, 4317, 4318, 4319, 4320,
4321, 4322, 4323, 4324, 4325, 4326, 4327, 4328, 4329, 4330, 4331,
4332, 4333, 4334, 4335, 4336, 4337, 4338, 4339, 4340, 4341, 4342,
4343, 4344, 4345, 4346, 4347, 4348, 4349, 4350, 4351, 4352, 4353,
4354, 4355, 4356, 4357, 4358, 4359, 4360, 4361, 4362, 4363, 4364,
4365, 4366, 4367, 4368, 4369, 4370, 4371, 4372, 4373, 4374, 4375,
4376, 4377, 4378, 4379, 4380, 4381, 4382, 4383, 4384, 4385, 4386,
4387, 4388, 4389, 4390, 4391, 4392, 4393, 4394, 4395, 4396, 4397,
4398, 4399, 4400, 4401, 4402, 4403, 4404, 4405, 4406, 4407, 4408,
4409, 4410, 4411, 4412, 4413, 4414, 4415, 4416, 4417, 4418, 4419,
4420, 4421, 4422, 4423, 4424, 4425, 4426, 4427, 4428, 4429, 4430,
4431, 4432, 4433, 4434, 4435, 4436, 4437, 4438, 4439, 4440, 4441,
4442, 4443, 4444, 4445, 4446, 4447, 4448, 4449, 4450, 4451, 4452,
4453, 4454, 4455, 4456, 4457, 4458, 4459, 4460, 4461, 4462, 4463,
4464, 4465, 4466, 4467, 4468, 4469, 4470, 4471, 4472), class = "Date"),
jday = c(244, 245, 246, 247, 248, 249, 250, 251, 252, 253,
254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265,
266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277,
278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289,
290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301,
302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313,
314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325,
326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337,
338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349,
350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361,
362, 363, 364, 365, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72,
73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87,
88, 89, 90), irrigation = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 68.999106583086, 0.613825511006476, 0.650504269646209,
0.675321041959003, 1.07386107583648, 0.704743246430332, 0.707284723670737,
0.776293467549444, 0.755267782118714, 1.18487391425568, 0.845114328328846,
0.823802762818568, 0.870540767040068, 0.939387145551663,
0.980778073801578, 0.961748234276633, 1.00175189046026, 1.2003019943978,
1.08581774443099, 1.02293983015042, 1.02830459076224, 0.841190189991182,
0.980525840833349, 1.10596434583942, 1.16474588634898, 1.13363473392227,
1.3104655997267, 1.04313889290523, 1.12900495066226, 1.14512528725041,
1.15993003474856, 1.36629089799899, 1.35725439867927, 1.41586446299136,
1.46648144027562, 1.20177115282966, 1.2724354938396, 1.17885413679104,
1.50501941940159, 1.61153108170889, 1.59654419167528, 1.57815025848092,
1.69451670970732, 1.90409241833733, 1.96138691207738, 2.31347289594632,
2.62349860182086, 2.02034176206126, 2.43931099974993, 2.80426669815212,
3.64748623301682, 3.61020936317814, 3.56980733038152, 4.2411068481149,
3.56775806019607, 4.05131195586862, 4.10309786009557, 3.82752398148324,
3.64170968879774, 3.72256845640905, 4.52625782049975, 3.77543871611067,
3.83794749361797, 3.57695659155985, 4.00032328633429, 4.00259658665333,
4.33779646123497, 3.9441870717169, 3.87438364862238, 3.42668787021081,
3.00505732564093, 3.26796355756741, 3.20416667160479, 4.02001638319886,
4.12818549443217, 3.56875502947465, 3.40190915228094, 3.97419348040831,
3.80111025838019, 4.26330353449849, 3.45396023352169, 3.31773448684841,
3.56689567936277, 4.24906589915452, 3.61606846040892, 3.71226018146404,
3.91100839040812, 4.01828006633277, 4.16464814862001, 3.7494809419206,
3.759374359279, 4.36243338723784, 0, 0.279377742878442, 3.12715397066283,
4.96814538900135, 5.27112768228772, 5.37505629456159, 5.80227566691278,
5.68143063147091, 5.76655560095333, 6.02031850351871, 5.72975780894455,
5.77516228018455, 5.40222501291812, 5.21530269882054, 5.86467400337886,
5.47526718806295, 5.20959328216256, 4.8062177676599, 5.08492012394285,
5.14194736665892, 5.55457368869226, 4.99883698028268, 5.17854310933826,
5.40636266319497, 4.97066477432992, 4.879204407479, 4.66249571494686,
4.63900838314908, 4.40660802600453, 4.42912446179436, 4.31494981339834,
3.53431485000166, 3.65618335390554, 3.26147690560054, 3.4740653732448,
3.21587573671804, 3.68968358086151, 2.59795268530985, 2.81539502190155,
2.96434859859133, 2.93298987971926, 2.61560347473737, 3.65341749469053,
2.8604916137399, 3.15716915686154, 3.10825421972182, 3.41439628601074,
3.00367127575921, 2.73676940769825, 2.89370579395479, 2.99327868859745,
2.49745100447275, 2.18776641771631, 2.18157188637743, 2.25322256736385,
2.39152978693397, 1.64653250314657, 0.287038117936514, 0.247974432787849,
0.245568821731123, 0.225235263120781, 0.239999308169467,
0.264739379142095, 0.292488079626583, 0.253238603906724,
0.291291301690259, 0.220847472403813, 0.00379066096926198,
0.00399085850391573, 0.00137884639999242, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), cumIrri = c(0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 68.999106583086, 69.6129320940925,
70.2634363637387, 70.9387574056977, 72.0126184815342, 72.7173617279645,
73.4246464516353, 74.2009399191847, 74.9562077013034, 76.1410816155591,
76.9861959438879, 77.8099987067065, 78.6805394737466, 79.6199266192983,
80.6007046930998, 81.5624529273765, 82.5642048178367, 83.7645068122345,
84.8503245566655, 85.8732643868159, 86.9015689775782, 87.7427591675694,
88.7232850084027, 89.8292493542421, 90.9939952405911, 92.1276299745134,
93.4380955742401, 94.4812344671453, 95.6102394178076, 96.755364705058,
97.9152947398065, 99.2815856378055, 100.638840036485, 102.054704499476,
103.521185939752, 104.722957092581, 105.995392586421, 107.174246723212,
108.679266142614, 110.290797224323, 111.887341415998, 113.465491674479,
115.160008384186, 117.064100802523, 119.025487714601, 121.338960610547,
123.962459212368, 125.982800974429, 128.422111974179, 131.226378672331,
134.873864905348, 138.484074268526, 142.053881598908, 146.294988447023,
149.862746507219, 153.914058463087, 158.017156323183, 161.844680304666,
165.486389993464, 169.208958449873, 173.735216270373, 177.510654986483,
181.348602480101, 184.925559071661, 188.925882357995, 192.928478944649,
197.266275405884, 201.210462477601, 205.084846126223, 208.511533996434,
211.516591322075, 214.784554879642, 217.988721551247, 222.008737934446,
226.136923428878, 229.705678458353, 233.107587610634, 237.081781091042,
240.882891349422, 245.146194883921, 248.600155117442, 251.917889604291,
255.484785283653, 259.733851182808, 263.349919643217, 267.062179824681,
270.973188215089, 274.991468281422, 279.156116430042, 282.905597371962,
286.664971731241, 291.027405118479, 291.027405118479, 291.306782861358,
294.433936832021, 299.402082221022, 304.67320990331, 310.048266197871,
315.850541864784, 321.531972496255, 327.298528097208, 333.318846600727,
339.048604409671, 344.823766689856, 350.225991702774, 355.441294401595,
361.305968404974, 366.781235593037, 371.990828875199, 376.797046642859,
381.881966766802, 387.023914133461, 392.578487822153, 397.577324802436,
402.755867911774, 408.162230574969, 413.132895349299, 418.012099756778,
422.674595471725, 427.313603854874, 431.720211880878, 436.149336342673,
440.464286156071, 443.998601006073, 447.654784359978, 450.916261265579,
454.390326638824, 457.606202375542, 461.295885956403, 463.893838641713,
466.709233663614, 469.673582262206, 472.606572141925, 475.222175616662,
478.875593111353, 481.736084725093, 484.893253881954, 488.001508101676,
491.415904387687, 494.419575663446, 497.156345071144, 500.050050865099,
503.043329553697, 505.540780558169, 507.728546975886, 509.910118862263,
512.163341429627, 514.554871216561, 516.201403719708, 516.488441837644,
516.736416270432, 516.981985092163, 517.207220355284, 517.447219663453,
517.711959042595, 518.004447122222, 518.257685726129, 518.548977027819,
518.769824500223, 518.773615161192, 518.777606019696, 518.778984866096,
518.778984866096, 518.778984866096, 518.778984866096, 518.778984866096,
518.778984866096, 518.778984866096, 518.778984866096, 518.778984866096,
518.778984866096, 518.778984866096, 518.778984866096, 518.778984866096,
518.778984866096, 518.778984866096, 518.778984866096, 518.778984866096,
518.778984866096, 518.778984866096, 518.778984866096, 518.778984866096
)), .Names = c("date", "jday", "irrigation", "cumIrri"), row.names = 610:821, class = "data.frame")
我正在尝试使用ggplot2绘制这个时间序列，但是显示了julian日（从年初开始经过的那一天）而不是x轴上的实际日期。
问题在于ggplot坚持将数据绘制为连续的，即使我需要绘制数据的顺序＆＃34;按原样＃34;。
例如，比较一下：
library(ggplot2)
ggplot(df, aes(x=jday)) + geom_line(aes(y=irrigation), size=1)
如果我绘制实际日期，我得到的是：
ggplot(df, aes(x=date)) + geom_line(aes(y=irrigation), size=1)
我怎样才能克服这个？
答案 0 :(得分：2)
根据我从ggplot2讨论列表中得到的回复，这就是得到我需要的答案：
library(scales)
ggplot(df, aes(x=date)) + geom_line(aes(y=irrigation), size=1) + scale_x_date(labels=date_format('%j'))
使用比例scale_x_date一样简单地绘制日期并将其格式化为朱利安日。