R t将基于行的函数应用于子集

我不熟悉

tapply

函数，没有在每个请求的子集内成功计算时差

我有一个输入数据框，其中包含一些RN的观察日期（列

DATE

）。在我的脚本中，我将这个数据帧子集到另一个（我们称之为

DF

）中，将数据限制在一个RN中

我试图自动计算一个日期和前一个日期之间的差异。我可以使用以下代码在

DF

上执行此操作：

as.numeric(c(NA, as.Date(tail(DF$DATE,-1)) - as.Date(head(DF$DATE,-1)) ))

我需要根据3个变量（

VAR1

，

VAR2

，

VAR3

）在每个子集中运行此操作，因此我尝试了所谓的

tapply

我试过：（

DATE

是我的第三列）

我可能错过了这里的一个要点，因为它返回一个数组，其中填充了大量的

NULL

。最糟糕的是，它返回所有站点的

NULL

数据，这些数据不存在于

DF

中

该函数调用的因子级别甚至不在输入中，这是怎么回事？有没有一种方法可以跳过所有这些

NULL

数据，或者至少在我的子集边界上限制它

我搜索了SO和其他帮助网站，但没有找到有效的答案

第二个问题：我想把输出（时差）写在一个新的列中。既然

tapply

结果是一个数组，我该怎么做？我必须把这个命令放在哪里？在

函数（x）{}

部分中还是在

应用

命令之外

编辑：这是DF的一部分，我也编辑了命令 编辑2：在做dput时，我发现我所有的因子水平仍然存在。我用factor（）删除了它们，但现在tapply（）不再工作了

编辑3:@sgibb:我尝试了您的命令，但现在得到另一个错误：“as.Date.numeric（值）中的错误：'必须提供源代码'”。因此，我试图提供一个原点，如下所示，但仍然得到了错误

SUBTOT$DIFF <- ave(SUBTOT$DATE, SUBTOT$SITE, SUBTOT$YEAR, SUBTOT$SP, FUN=function(x) {
as.numeric(c(NA, as.Date(tail(x,-1),origin="1960-10-01") -      as.Date(head(x,-1),origin="1960-10-01")))})


dput(head(SUBTOT,n=100))
structure(list(YEAR = structure(c(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("1994", 
"1995", "1996", "1997", "1998", "1999", "2000", "2001", "2002", 
"2003", "2004", "2005", "2006", "2007", "2008", "2009", "2010", 
"2011", "2012"), class = "factor"), RN = structure(c(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 = "RNN144", class = "factor"), DATE = c("1994-04-16", 
"1994-07-23", "1994-10-01", "1994-04-16", "1994-05-07", "1994-10-01", 
"1994-04-16", "1994-07-05", "1994-07-10", "1994-07-17", "1994-10-01", 
"1994-04-16", "1994-06-20", "1994-10-01", "1994-04-16", "1994-06-06", 
"1994-10-01", "1994-04-16", "1994-07-23", "1994-10-01", "1994-04-16", 
"1994-09-19", "1994-09-24", "1994-10-01", "1994-04-16", "1994-04-23", 
"1994-04-30", "1994-05-07", "1994-05-23", "1994-05-29", "1994-07-10", 
"1994-07-17", "1994-07-23", "1994-08-08", "1994-10-01", "1994-04-16", 
"1994-07-17", "1994-07-23", "1994-10-01", "1994-04-16", "1994-07-17", 
"1994-10-01", "1994-04-16", "1994-07-05", "1994-07-10", "1994-07-17", 
"1994-07-23", "1994-08-20", "1994-10-01", "1994-04-16", "1994-06-28", 
"1994-07-05", "1994-07-10", "1994-10-01", "1994-04-16", "1994-06-20", 
"1994-06-28", "1994-10-01", "1994-04-16", "1994-07-17", "1994-07-23", 
"1994-08-20", "1994-08-27", "1994-09-04", "1994-10-01", "1994-04-16", 
"1994-08-20", "1994-09-19", "1994-09-24", "1994-10-01", "1994-04-16", 
"1994-05-29", "1994-10-01", "1994-04-16", "1994-07-10", "1994-07-17", 
"1994-07-23", "1994-07-29", "1994-08-20", "1994-08-27", "1994-10-01", 
"1994-04-16", "1994-07-05", "1994-07-17", "1994-10-01", "1994-04-16", 
"1994-07-17", "1994-10-01", "1994-04-16", "1994-05-23", "1994-10-01", 
"1994-04-23", "1994-07-05", "1994-07-17", "1994-07-23", "1994-09-20", 
"1994-04-23", "1994-05-23", "1994-05-29", "1994-09-20"), NOM = structure(c(16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L, 
16L, 16L, 16L, 16L, 16L, 16L, 16L, 16L), .Label = c("ANCIENNES CARRIERES D'ORIVAL", 
"BAIE DE L'AIGUILLON (VENDEE)", "CHERINE", "COMBE LAVAUX-JEAN ROLAND", 
"COTE DE MANCY", "Espace protégé - code", "ESTAGNOL", "GRAND PIERRE ET VITAIN", 
"ILE DE LA PLATIERE", "LAC DE REMORAY", "MARAIS DE LAVOURS", 
"PETITE CAMARGUE ALSACIENNE", "PINAIL", "RAMIERES DU VAL DE DROME", 
"RAVIN DE VALBOIS", "TOURBIERE DES DAUGES"), class = "factor"), 
SITE = structure(c(104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 104L, 
104L, 104L, 104L, 104L, 105L, 105L, 105L, 105L, 105L, 105L, 
105L, 105L, 105L), .Label = c("Libellé du site", "RNN027-Estagnol 01", 
"RNN027-Estagnol 02", "RNN027-Estagnol 03", "RNN027-Estagnol 04", 
"RNN027-Estagnol 05", "RNN027-Estagnol 06", "RNN037-GPV 01", 
"RNN037-GPV 02", "RNN037-GPV 03", "RNN037-GPV 04", "RNN037-GPV 05", 
"RNN044-Pinail A", "RNN044-Pinail B", "RNN044-Pinail C", 
"RNN044-Pinail D", "RNN044-Pinail E", "RNN044-Pinail F", 
"RNN044-Pinail G", "RNN044-Pinail I", "RNN044-Pinail J", 
"RNN044-Pinail K", "RNN046-Remoray 01", "RNN046-Remoray 02", 
"RNN046-Remoray 03", "RNN046-Remoray 04", "RNN046-Remoray 05", 
"RNN046-Remoray 06", "RNN046-Remoray 07", "RNN046-Remoray 08", 
"RNN046-Remoray 09", "RNN046-Remoray 10", "RNN060-PCA Canal", 
"RNN060-PCA Heid", "RNN060-PCA Luzernière", "RNN060-PCA Mitlere-au", 
"RNN060-PCA Petite Heid", "RNN066-Valbois Ourlet bas", "RNN066-Valbois Ourlet haut", 
"RNN066-Valbois Pel Humbert", "RNN066-Valbois Pel Martin", 
"RNN066-Valbois Pel Podgo", "RNN066-Valbois Pel Podgo corniche", 
"RNN066-Valbois Pel temoin", "RNN066-Valbois Vignes parc2bas", 
"RNN066-Valbois Vignes parc2haut", "RNN066-Valbois Vignes parc3bas", 
"RNN066-Valbois Vignes parc3haut", "RNN068-Marais Lavours beon1", 
"RNN068-Marais Lavours beon2", "RNN068-Marais Lavours beon3", 
"RNN068-Marais Lavours beon4", "RNN068-Marais Lavours beon5", 
"RNN068-Marais Lavours ceyzerieu1", "RNN068-Marais Lavours culoz1", 
"RNN078-Chérine 01", "RNN078-Chérine 02", "RNN078-Chérine 03", 
"RNN078-Chérine 04", "RNN078-Chérine 05", "RNN078-Chérine 06", 
"RNN078-Chérine 07", "RNN078-Chérine 08", "RNN078-Chérine 09", 
"RNN078-Chérine 10", "RNN078-Chérine 11", "RNN078-Chérine 12", 
"RNN079-Platière 01LGRA01", "RNN079-Platière 01LGRA03", "RNN079-Platière 01LGRA04", 
"RNN079-Platière 01LGRA07", "RNN079-Platière 01LGRA08", "RNN079-Platière 01LGRA11", 
"RNN079-Platière 01LGRA12", "RNN079-Platière 01LPGO01", "RNN079-Platière 01LPGO02", 
"RNN079-Platière 01LPGO03", "RNN079-Platière 01LPGO04", "RNN079-Platière 01LPGO05", 
"RNN079-Platière 01LPGO06", "RNN079-Platière 01LPGO07", "RNN079-Platière 01LPOV01", 
"RNN079-Platière 01LPOV02", "RNN079-Platière 01LPOV03", "RNN079-Platière 01LPOV04", 
"RNN079-Platière 01LPOV05", "RNN079-Platière 01LPOV06", "RNN089-Ramières 24", 
"RNN089-Ramières 25", "RNN089-Ramières 26", "RNN089-Ramières 27", 
"RNN089-Ramières 35", "RNN089-Ramières 36", "RNN089-Ramières 37", 
"RNN089-Ramières 43", "RNN089-Ramières 46", "RNN089-Ramières 47", 
"RNN130-Baie Aiguillon Charron-Casiers-vase", "RNN130-Baie Aiguillon Charron-Mizottes-Chaînes", 
"RNN130-Baie Aiguillon Charron-Pd-Digue-mer", "RNN130-Baie Aiguillon Triaize-Mizottes", 
"RNN130-Baie Aiguillon Triaize-Pd-Digue-1", "RNN130-Baie Aiguillon Triaize-Pd-Digue-2", 
"RNN144-Dauges 01", "RNN144-Dauges 02", "RNN144-Dauges 03", 
"RNN144-Dauges 04", "RNN144-Dauges 05", "RNN144-Dauges 06", 
"RNN144-Dauges 07", "RNN144-Dauges 08", "RNN144-Dauges 09", 
"RNN144-Dauges 10", "RNN144-Dauges 11", "RNN144-Dauges 12", 
"RNN144-Dauges 13", "RNN144-Dauges 14", "RNN144-Dauges 15", 
"RNN157-Combe Lavaux 01 Sentier des crêtes", "RNN157-Combe Lavaux 02 Sentier des dalles", 
"RNN157-Combe Lavaux 03 Plain des Essoyottes partie humide", 
"RNN157-Combe Lavaux 04 Plain des Essoyottes partie sèches", 
"RNN157-Combe Lavaux 05 Pelouses de Fontenottes", "RNN157-Combe Lavaux 06 Friches parc de nuit", 
"RNN157-Combe Lavaux 07 Friches", "RNN157-Combe Lavaux 08 Friches ouverture ONF", 
"RNN157-Combe Lavaux 09 Haut du Champ Sement", "RNN157-Combe Lavaux 10 Bas du Champ Sement", 
"RNR117-TRMANCY 01", "RNR117-TRMANCY 02", "RNR117-TRMANCY 03", 
"RNR117-TRMANCY 04", "RNR117-TRMANCY 05", "RNR117-TRMANCY 06", 
"RNR189-RNR_TRACO_01", "RNR189-RNR_TRACO_02", "RNR189-RNR_TRACO_03", 
"RNR189-RNR_TRACO_04", "RNR189-RNR_TRACO_05", "RNR189-RNR_TRACO_06a", 
"RNR189-RNR_TRACO_06b", "RNR189-RNR_TRACO_07", "RNR189-RNR_TRACO_08", 
"RNR189-RNR_TRACO_09a", "RNR189-RNR_TRACO_09b", "RNR189-RNR_TRACO_10", 
"RNR189-RNR_TRACO_11", "RNR189-RNR_TRACO_12", "RNR189-RNR_TRACO_13", 
"RNR189-RNR_TRACO_14", "RNR189-RNR_TRACO_15"), class = "factor"), 
LONG = c(80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 
80, 80, 80, 80, 115, 115, 115, 115, 115, 115, 115, 115, 115
), SP = structure(c(1L, 1L, 1L, 2L, 2L, 2L, 4L, 4L, 4L, 4L, 
4L, 5L, 5L, 5L, 10L, 10L, 10L, 12L, 12L, 12L, 20L, 20L, 20L, 
20L, 29L, 29L, 29L, 29L, 29L, 29L, 29L, 29L, 29L, 29L, 29L, 
31L, 31L, 31L, 31L, 33L, 33L, 33L, 43L, 43L, 43L, 43L, 43L, 
43L, 43L, 44L, 44L, 44L, 44L, 44L, 56L, 56L, 56L, 56L, 61L, 
61L, 61L, 61L, 61L, 61L, 61L, 62L, 62L, 62L, 62L, 62L, 69L, 
69L, 69L, 70L, 70L, 70L, 70L, 70L, 70L, 70L, 70L, 72L, 72L, 
72L, 72L, 73L, 73L, 73L, 75L, 75L, 75L, 4L, 4L, 4L, 4L, 4L, 
15L, 15L, 15L, 15L), .Label = c("Aglais urticae (Linnaeus, 1758)", 
"Anthocharis cardamines (Linnaeus, 1758)", "Apatura iris (Linnaeus, 1758)", 
"Aphantopus hyperantus (Linnaeus, 1758)", "Aporia crataegi (Linnaeus, 1758)", 
"Araschnia levana (Linnaeus, 1758)", "Argynnis aglaja (Linnaeus, 1758)", 
"Argynnis paphia (Linnaeus, 1758)", "Boloria dia (Linnaeus, 1767)", 
"Boloria euphrosyne (Linnaeus, 1758)", "Boloria selene (Denis & Schiffermüller, 1775)", 
"Brenthis daphne (Bergsträsser, 1780)", "Brintesia circe (Fabricius, 1775)", 
"Callophrys rubi (Linnaeus, 1758)", "Carterocephalus palaemon (Pallas, 1771)", 
"Celastrina argiolus (Linnaeus, 1758)", "Clossiana dia (Linnaeus, 1767)", 
"Clossiana selene (Denis & Schiffermüller, 1775)", "Coenonympha pamphilus (Linnaeus, 1758)", 
"Colias croceus (Fourcroy, 1785)", "Colias hyale (Linnaeus, 1758)", 
"Colias PC (hyale / alfacariensis) #complexe", "Cupido argiades (Pallas, 1771)", 
"Erebia meolans (de Prunner, 1798)", "Erynnis tages (Linnaeus, 1758)", 
"Euchloe PC (ausonia / simplonia) #complexe", "Euphydryas aurinia (Rottemburg, 1775)", 
"Everes argiades (Pallas, 1771)", "Gonepteryx rhamni (Linnaeus, 1758)", 
"Hesperia comma (Linnaeus, 1758)", "Heteropterus morpheus (Pallas, 1771)", 
"Hipparchia fagi (Scopoli, 1763)", "Inachis io (Linnaeus, 1758)", 
"Iphiclides podalirius (Linnaeus, 1758)", "Issoria lathonia (Linnaeus, 1758)", 
"Ladoga camilla (Linnaeus, 1764)", "Lampides boeticus (Linnaeus, 1767)", 
"Lasiommata megera (Linnaeus, 1767)", "Limenitis camilla (Linnaeus, 1764)", 
"Limenitis reducta Staudinger, 1901", "Lycaena phlaeas (Linnaeus, 1761)", 
"Lycaena tityrus (Poda, 1761)", "Maniola jurtina (Linnaeus, 1758)", 
"Melanargia galathea (Linnaeus, 1758)", "Melitaea cinxia (Linnaeus, 1758)", 
"Melitaea diamina (Lang, 1789)", "Melitaea didyma (Esper, 1778)", 
"Melitaea phoebe (Denis & Schiffermüller, 1775)", "Mellicta athalia (Rottemburg, 1775)", 
"Mellicta C (athalia / deione / parthenoides) #complexe", 
"Mellicta parthenoides (Keferstein, 1851)", "Mesoacidalia aglaja (Linnaeus, 1758)", 
"Nymphalis antiopa (Linnaeus, 1758)", "Nymphalis polychloros (Linnaeus, 1758)", 
"Ochlodes venatus (Bremer & Grey, 1853)", "Ochlodes venatus faunus (Turati, 1905)", 
"Papilio machaon Linnaeus, 1758", "Pararge aegeria (Linnaeus, 1758)", 
"Pieris 2 (rapae / mannii / napi) #complexe", "Pieris brassicae (Linnaeus, 1758)", 
"Pieris napi (Linnaeus, 1758)", "Pieris PC (rapae / mannii) #complexe", 
"Plebeius agestis (Denis & Schiffermüller, 1775)", "Plebejus argus (Linnaeus, 1758)", 
"Polygonia c-album (Linnaeus, 1758)", "Polyommatus icarus (Rottemburg, 1775)", 
"Polyommatus semiargus (Rottemburg, 1775)", "Pseudophilotes baton (Bergsträsser, 1779)", 
"Pyrgus 1 C (malvae / malvoides) #complexe", "Pyronia tithonus (Linnaeus, 1767)", 
"Quercusia quercus (Linnaeus, 1758)", "Thymelicus lineola (Ochsenheimer, 1808)", 
"Thymelicus sylvestris (Poda, 1761)", "Vanessa atalanta (Linnaeus, 1758)", 
"Vanessa cardui (Linnaeus, 1758)"), class = "factor"), SUMNB = c(0, 
2, 0, 0, 2, 0, 0, 12, 18, 2, 0, 0, 2, 0, 0, 2, 0, 0, 2, 0, 
0, 4, 2, 0, 0, 2, 2, 2, 2, 6, 2, 2, 4, 2, 0, 0, 2, 2, 0, 
0, 2, 0, 0, 2, 2, 2, 6, 6, 0, 0, 4, 4, 4, 0, 0, 4, 2, 0, 
0, 2, 2, 4, 2, 2, 0, 0, 4, 2, 2, 0, 0, 2, 0, 0, 2, 2, 6, 
4, 2, 4, 0, 0, 2, 2, 0, 0, 4, 0, 0, 2, 0, 0, 4, 6, 2, 0, 
0, 2, 2, 0), NB100 = c(0, 2.5, 0, 0, 2.5, 0, 0, 15, 22.5, 
2.5, 0, 0, 2.5, 0, 0, 2.5, 0, 0, 2.5, 0, 0, 5, 2.5, 0, 0, 
2.5, 2.5, 2.5, 2.5, 7.5, 2.5, 2.5, 5, 2.5, 0, 0, 2.5, 2.5, 
0, 0, 2.5, 0, 0, 2.5, 2.5, 2.5, 7.5, 7.5, 0, 0, 5, 5, 5, 
0, 0, 5, 2.5, 0, 0, 2.5, 2.5, 5, 2.5, 2.5, 0, 0, 5, 2.5, 
2.5, 0, 0, 2.5, 0, 0, 2.5, 2.5, 7.5, 5, 2.5, 5, 0, 0, 2.5, 
2.5, 0, 0, 5, 0, 0, 2.5, 0, 0, 3.47826086956522, 5.21739130434783, 
1.73913043478261, 0, 0, 1.73913043478261, 1.73913043478261, 
0)), .Names = c("YEAR", "RN", "DATE", "NOM", "SITE", "LONG", 
"SP", "SUMNB", "NB100"), class = c("data.table", "data.frame"
), row.names = c(NA, -100L), .internal.selfref = <pointer: 0x0000000000210788>)

---

小计$DIFF可能您不需要查找
tapply
，而是查找
ave
（有关详细信息，请参见
？ave
）

我创建了一个简化的示例数据集：

## create example dataset
set.seed(1)
df <- data.frame(YEAR=rep(2001:2005, each=4), MONTH=rep(1:10, each=2),
                 DAY=rep(1:10, each=2),
                 VALUE=sample(1:20))

## turn YEAR, MONTH, DAY into factors
df <- within(df, {
  YEAR <- factor(YEAR)
  MONTH <- factor(MONTH)
  DAY <- factor(DAY)
})

## your function (simplified for my example)
your_function <- function(x) {
  as.numeric(c(NA, tail(x, -1)-head(x,-1)))
}

## run `your_function` for equal combinations of YEAR, MONTH, DAY
df$DIFF <- ave(df$VALUE, df$YEAR, df$MONTH, df$DAY, FUN=your_function)
df
#   YEAR MONTH DAY VALUE DIFF
#1  2001     1   1     6   NA
#2  2001     1   1     8    2
#3  2001     2   2    11   NA
#4  2001     2   2    16    5
#5  2002     3   3     4   NA
#6  2002     3   3    14   10
#7  2002     4   4    15   NA
#8  2002     4   4     9   -6
#9  2003     5   5    19   NA
#10 2003     5   5     1  -18
#11 2003     6   6     3   NA
#12 2003     6   6     2   -1
#13 2004     7   7    20   NA
#14 2004     7   7    10  -10
#15 2004     8   8     5   NA
#16 2004     8   8     7    2
#17 2005     9   9    12   NA
#18 2005     9   9    17    5
#19 2005    10  10    18   NA
#20 2005    10  10    13   -5

创建示例数据集
种子（1）
df请提供您的数据样本，例如使用
dput
进行此操作。请按照@Thomas advice操作
dput
您的样本数据。对于变量内和变量之间的空格，读取起来有点棘手。请仅包括与您的问题相关的变量。如果您正在这样做，请参阅编辑2。乍一看，它似乎正在工作。但是当我尝试使用我的数据时，我得到了一些错误和警告：在
[@user2542995:请查看我的编辑。我添加了一行适合我的代码。我最终使用zoo包和as.Date.numeric运行了它。非常感谢您的帮助！干杯！
## create example dataset
set.seed(1)
df <- data.frame(YEAR=rep(2001:2005, each=4), MONTH=rep(1:10, each=2),
                 DAY=rep(1:10, each=2),
                 VALUE=sample(1:20))

## turn YEAR, MONTH, DAY into factors
df <- within(df, {
  YEAR <- factor(YEAR)
  MONTH <- factor(MONTH)
  DAY <- factor(DAY)
})

## your function (simplified for my example)
your_function <- function(x) {
  as.numeric(c(NA, tail(x, -1)-head(x,-1)))
}

## run `your_function` for equal combinations of YEAR, MONTH, DAY
df$DIFF <- ave(df$VALUE, df$YEAR, df$MONTH, df$DAY, FUN=your_function)
df
#   YEAR MONTH DAY VALUE DIFF
#1  2001     1   1     6   NA
#2  2001     1   1     8    2
#3  2001     2   2    11   NA
#4  2001     2   2    16    5
#5  2002     3   3     4   NA
#6  2002     3   3    14   10
#7  2002     4   4    15   NA
#8  2002     4   4     9   -6
#9  2003     5   5    19   NA
#10 2003     5   5     1  -18
#11 2003     6   6     3   NA
#12 2003     6   6     2   -1
#13 2004     7   7    20   NA
#14 2004     7   7    10  -10
#15 2004     8   8     5   NA
#16 2004     8   8     7    2
#17 2005     9   9    12   NA
#18 2005     9   9    17    5
#19 2005    10  10    18   NA
#20 2005    10  10    13   -5

DF$DIFF <- ave(DF$DATE, DF$SITE, DF$YEAR, DF$SP, FUN=function(x) {
   as.numeric(c(NA, as.Date(tail(x,-1)) - as.Date(head(x,-1)))))
}