获取区间导数最大值的位置（列名）
Retrieve the position (column name) of the maximum value of the derivative of an interval
为了计算红边位置指数，我需要找到从690nm到740nm的红边区域反射率的最大导数对应的波长值（列名）。我在下面包含了我的数据框的一个子集，它包含正确的间隔...
我有 640 行（样本）的 2151 个测量值（值）加上第一列中的一些分类（例如 plantType 和 plantCondition）。我需要找到对应于指定区间内值的导数的最大值的值的列和 return REPI 列的波长值。
我正在尝试这样的事情，但我不知道如何计算指定区间内导数的最大值
# find the maximum of the derivative of the values in columns x690:x740
# attempt to find for single sample first
> which( colnames(spec.data)=="X690")
[1] 352
> which( colnames(spec.data)=="X740")
[1] 402
# I want to return the values of the differential but this doesn't work
> foo.vector <- diff(spec.data[1,352:402])
>> Error in r[i1] - r[-length(r):-(length(r) - lag + 1L)] : non-numeric argument to binary operator
这是有道理的，因为我在dx/dt中没有dt，但我不确定如何检索这个区间的导数最大值的位置。一旦我这样做了，我想我会
> spec.data$REPI <- which( colnames(spec.data) == max(foo.vector))
然后我想我会 lapply 每行这样？
任何人都可以指出我的解决方案吗？
谢谢...
来自 dput
的数据子集
> dput(spec.data[1:2, c(1:3, 7, 300:450)])
structure(list(Sample = c("JUMO_G1 P1T9 Leaf Clip00000.asd",
"JUMO_G1 P1T9 Leaf Clip00001.asd"), plantType = c("JUMO", "JUMO"
), plantCondition = c("G", "G"), REPI = c(NA_real_, NA_real_),
X638 = c(0.0611, 0.06114), X639 = c(0.0606, 0.06064), X640 = c(0.0601,
0.06012), X641 = c(0.0595, 0.05953), X642 = c(0.0589, 0.05893
), X643 = c(0.0584, 0.05834), X644 = c(0.0577, 0.05775),
X645 = c(0.05717, 0.05717), X646 = c(0.0566, 0.05664), X647 = c(0.0562,
0.05618), X648 = c(0.0557, 0.05573), X649 = c(0.0554, 0.05536
), X650 = c(0.0551, 0.05505), X651 = c(0.0547, 0.05475),
X652 = c(0.05448, 0.05447), X653 = c(0.0542, 0.05421), X654 = c(0.054,
0.05395), X655 = c(0.0536, 0.05357), X656 = c(0.0532, 0.05319
), X657 = c(0.0528, 0.05277), X658 = c(0.0523, 0.05229),
X659 = c(0.0518, 0.05176), X660 = c(0.05128, 0.05126), X661 = c(0.0508,
0.05077), X662 = c(0.0503, 0.05024), X663 = c(0.0498, 0.04978
), X664 = c(0.0494, 0.04936), X665 = c(0.049, 0.04897), X666 = c(0.04869,
0.04866), X667 = c(0.0484, 0.04838), X668 = c(0.0482, 0.04815
), X669 = c(0.048, 0.04797), X670 = c(0.0479, 0.04782), X671 = c(0.0478,
0.04775), X672 = c(0.0478, 0.04773), X673 = c(0.0478, 0.04773
), X674 = c(0.0478, 0.04776), X675 = c(0.0479, 0.04786),
X676 = c(0.0481, 0.04802), X677 = c(0.0483, 0.0482), X678 = c(0.0486,
0.04843), X679 = c(0.0489, 0.04873), X680 = c(0.04925, 0.04911
), X681 = c(0.0498, 0.04962), X682 = c(0.0504, 0.05026),
X683 = c(0.05122, 0.05103), X684 = c(0.0522, 0.052), X685 = c(0.0533,
0.05317), X686 = c(0.0548, 0.05458), X687 = c(0.05647, 0.05627
), X688 = c(0.0584, 0.05824), X689 = c(0.0608, 0.06057),
X690 = c(0.0634, 0.06326), X691 = c(0.0664, 0.06626), X692 = c(0.0698,
0.06958), X693 = c(0.0734, 0.07317), X694 = c(0.0773, 0.07701
), X695 = c(0.0814, 0.08109), X696 = c(0.0856, 0.0854), X697 = c(0.0901,
0.08989), X698 = c(0.0947, 0.09449), X699 = c(0.0994, 0.09917
), X700 = c(0.10417, 0.10395), X701 = c(0.10899, 0.10881),
X702 = c(0.11385, 0.11366), X703 = c(0.11871, 0.11854), X704 = c(0.12356,
0.12342), X705 = c(0.1284, 0.12829), X706 = c(0.13324, 0.13312
), X707 = c(0.13803, 0.13792), X708 = c(0.14281, 0.14273),
X709 = c(0.14763, 0.14755), X710 = c(0.15243, 0.15235), X711 = c(0.15718,
0.15713), X712 = c(0.16192, 0.16189), X713 = c(0.1667, 0.16663
), X714 = c(0.17143, 0.17137), X715 = c(0.17609, 0.17605),
X716 = c(0.18069, 0.18062), X717 = c(0.18528, 0.1852), X718 = c(0.18977,
0.18968), X719 = c(0.19417, 0.19406), X720 = c(0.19851, 0.19838
), X721 = c(0.20276, 0.20263), X722 = c(0.20686, 0.20671),
X723 = c(0.2108, 0.21063), X724 = c(0.21465, 0.21449), X725 = c(0.21837,
0.21819), X726 = c(0.22194, 0.22174), X727 = c(0.22534, 0.22515
), X728 = c(0.2286, 0.22838), X729 = c(0.23164, 0.23142),
X730 = c(0.23447, 0.23427), X731 = c(0.23719, 0.23696), X732 = c(0.23984,
0.23959), X733 = c(0.24229, 0.24203), X734 = c(0.24452, 0.24426
), X735 = c(0.24668, 0.24638), X736 = c(0.24867, 0.24839),
X737 = c(0.25053, 0.25028), X738 = c(0.25229, 0.25203), X739 = c(0.25382,
0.25359), X740 = c(0.25531, 0.25508), X741 = c(0.25672, 0.25646
), X742 = c(0.25791, 0.25766), X743 = c(0.25907, 0.25884),
X744 = c(0.26014, 0.25993), X745 = c(0.2611, 0.26089), X746 = c(0.26201,
0.26178), X747 = c(0.26278, 0.26257), X748 = c(0.26347, 0.26329
), X749 = c(0.26414, 0.26397), X750 = c(0.26475, 0.26459),
X751 = c(0.26525, 0.2651), X752 = c(0.26568, 0.26554), X753 = c(0.26614,
0.266), X754 = c(0.26652, 0.26639), X755 = c(0.26682, 0.26671
), X756 = c(0.2671, 0.26701), X757 = c(0.26743, 0.26734),
X758 = c(0.26767, 0.26758), X759 = c(0.26789, 0.26781), X760 = c(0.26814,
0.26808), X761 = c(0.2682, 0.26817), X762 = c(0.26835, 0.26831
), X763 = c(0.26856, 0.26851), X764 = c(0.26872, 0.26869),
X765 = c(0.26884, 0.26881), X766 = c(0.26892, 0.2689), X767 = c(0.26896,
0.26894), X768 = c(0.26898, 0.26896), X769 = c(0.2691, 0.26909
), X770 = c(0.2692, 0.2692), X771 = c(0.26921, 0.26921),
X772 = c(0.26923, 0.26926), X773 = c(0.26927, 0.26931), X774 = c(0.26935,
0.26939), X775 = c(0.26945, 0.26947), X776 = c(0.26946, 0.26949
), X777 = c(0.26948, 0.26952), X778 = c(0.26953, 0.26958),
X779 = c(0.26958, 0.26963), X780 = c(0.26965, 0.2697), X781 = c(0.2697,
0.26975), X782 = c(0.2697, 0.26977), X783 = c(0.26972, 0.26978
), X784 = c(0.26979, 0.26982), X785 = c(0.26987, 0.2699),
X786 = c(0.26991, 0.26998), X787 = c(0.26989, 0.26997), X788 = c(0.26991,
0.26998)), .Names = c("Sample", "plantType", "plantCondition",
"REPI", "X638", "X639", "X640", "X641", "X642", "X643", "X644",
"X645", "X646", "X647", "X648", "X649", "X650", "X651", "X652",
"X653", "X654", "X655", "X656", "X657", "X658", "X659", "X660",
"X661", "X662", "X663", "X664", "X665", "X666", "X667", "X668",
"X669", "X670", "X671", "X672", "X673", "X674", "X675", "X676",
"X677", "X678", "X679", "X680", "X681", "X682", "X683", "X684",
"X685", "X686", "X687", "X688", "X689", "X690", "X691", "X692",
"X693", "X694", "X695", "X696", "X697", "X698", "X699", "X700",
"X701", "X702", "X703", "X704", "X705", "X706", "X707", "X708",
"X709", "X710", "X711", "X712", "X713", "X714", "X715", "X716",
"X717", "X718", "X719", "X720", "X721", "X722", "X723", "X724",
"X725", "X726", "X727", "X728", "X729", "X730", "X731", "X732",
"X733", "X734", "X735", "X736", "X737", "X738", "X739", "X740",
"X741", "X742", "X743", "X744", "X745", "X746", "X747", "X748",
"X749", "X750", "X751", "X752", "X753", "X754", "X755", "X756",
"X757", "X758", "X759", "X760", "X761", "X762", "X763", "X764",
"X765", "X766", "X767", "X768", "X769", "X770", "X771", "X772",
"X773", "X774", "X775", "X776", "X777", "X778", "X779", "X780",
"X781", "X782", "X783", "X784", "X785", "X786", "X787", "X788"
), row.names = 1:2, class = "data.frame")
你可以试试这个
spec.data$REPI <- apply(spec.data[,-(1:4)], 1, function(x) which.max(diff(x)))
或者您可以尝试使用 dplyr 和 tidyr:
library(dplyr)
library(tidyr)
spec.data %>%
gather(key, value, -Sample, -plantType, - plantCondition, -REPI) %>%
group_by(Sample) %>%
summarise(which.max(diff(value)))
他们似乎给出了相同的结果。
为了计算红边位置指数，我需要找到从690nm到740nm的红边区域反射率的最大导数对应的波长值（列名）。我在下面包含了我的数据框的一个子集，它包含正确的间隔...
我有 640 行（样本）的 2151 个测量值（值）加上第一列中的一些分类（例如 plantType 和 plantCondition）。我需要找到对应于指定区间内值的导数的最大值的值的列和 return REPI 列的波长值。
我正在尝试这样的事情，但我不知道如何计算指定区间内导数的最大值
# find the maximum of the derivative of the values in columns x690:x740
# attempt to find for single sample first
> which( colnames(spec.data)=="X690")
[1] 352
> which( colnames(spec.data)=="X740")
[1] 402
# I want to return the values of the differential but this doesn't work
> foo.vector <- diff(spec.data[1,352:402])
>> Error in r[i1] - r[-length(r):-(length(r) - lag + 1L)] : non-numeric argument to binary operator
这是有道理的，因为我在dx/dt中没有dt，但我不确定如何检索这个区间的导数最大值的位置。一旦我这样做了，我想我会
> spec.data$REPI <- which( colnames(spec.data) == max(foo.vector))
然后我想我会 lapply 每行这样？
任何人都可以指出我的解决方案吗？ 谢谢...
来自 dput
的数据子集> dput(spec.data[1:2, c(1:3, 7, 300:450)])
structure(list(Sample = c("JUMO_G1 P1T9 Leaf Clip00000.asd",
"JUMO_G1 P1T9 Leaf Clip00001.asd"), plantType = c("JUMO", "JUMO"
), plantCondition = c("G", "G"), REPI = c(NA_real_, NA_real_),
X638 = c(0.0611, 0.06114), X639 = c(0.0606, 0.06064), X640 = c(0.0601,
0.06012), X641 = c(0.0595, 0.05953), X642 = c(0.0589, 0.05893
), X643 = c(0.0584, 0.05834), X644 = c(0.0577, 0.05775),
X645 = c(0.05717, 0.05717), X646 = c(0.0566, 0.05664), X647 = c(0.0562,
0.05618), X648 = c(0.0557, 0.05573), X649 = c(0.0554, 0.05536
), X650 = c(0.0551, 0.05505), X651 = c(0.0547, 0.05475),
X652 = c(0.05448, 0.05447), X653 = c(0.0542, 0.05421), X654 = c(0.054,
0.05395), X655 = c(0.0536, 0.05357), X656 = c(0.0532, 0.05319
), X657 = c(0.0528, 0.05277), X658 = c(0.0523, 0.05229),
X659 = c(0.0518, 0.05176), X660 = c(0.05128, 0.05126), X661 = c(0.0508,
0.05077), X662 = c(0.0503, 0.05024), X663 = c(0.0498, 0.04978
), X664 = c(0.0494, 0.04936), X665 = c(0.049, 0.04897), X666 = c(0.04869,
0.04866), X667 = c(0.0484, 0.04838), X668 = c(0.0482, 0.04815
), X669 = c(0.048, 0.04797), X670 = c(0.0479, 0.04782), X671 = c(0.0478,
0.04775), X672 = c(0.0478, 0.04773), X673 = c(0.0478, 0.04773
), X674 = c(0.0478, 0.04776), X675 = c(0.0479, 0.04786),
X676 = c(0.0481, 0.04802), X677 = c(0.0483, 0.0482), X678 = c(0.0486,
0.04843), X679 = c(0.0489, 0.04873), X680 = c(0.04925, 0.04911
), X681 = c(0.0498, 0.04962), X682 = c(0.0504, 0.05026),
X683 = c(0.05122, 0.05103), X684 = c(0.0522, 0.052), X685 = c(0.0533,
0.05317), X686 = c(0.0548, 0.05458), X687 = c(0.05647, 0.05627
), X688 = c(0.0584, 0.05824), X689 = c(0.0608, 0.06057),
X690 = c(0.0634, 0.06326), X691 = c(0.0664, 0.06626), X692 = c(0.0698,
0.06958), X693 = c(0.0734, 0.07317), X694 = c(0.0773, 0.07701
), X695 = c(0.0814, 0.08109), X696 = c(0.0856, 0.0854), X697 = c(0.0901,
0.08989), X698 = c(0.0947, 0.09449), X699 = c(0.0994, 0.09917
), X700 = c(0.10417, 0.10395), X701 = c(0.10899, 0.10881),
X702 = c(0.11385, 0.11366), X703 = c(0.11871, 0.11854), X704 = c(0.12356,
0.12342), X705 = c(0.1284, 0.12829), X706 = c(0.13324, 0.13312
), X707 = c(0.13803, 0.13792), X708 = c(0.14281, 0.14273),
X709 = c(0.14763, 0.14755), X710 = c(0.15243, 0.15235), X711 = c(0.15718,
0.15713), X712 = c(0.16192, 0.16189), X713 = c(0.1667, 0.16663
), X714 = c(0.17143, 0.17137), X715 = c(0.17609, 0.17605),
X716 = c(0.18069, 0.18062), X717 = c(0.18528, 0.1852), X718 = c(0.18977,
0.18968), X719 = c(0.19417, 0.19406), X720 = c(0.19851, 0.19838
), X721 = c(0.20276, 0.20263), X722 = c(0.20686, 0.20671),
X723 = c(0.2108, 0.21063), X724 = c(0.21465, 0.21449), X725 = c(0.21837,
0.21819), X726 = c(0.22194, 0.22174), X727 = c(0.22534, 0.22515
), X728 = c(0.2286, 0.22838), X729 = c(0.23164, 0.23142),
X730 = c(0.23447, 0.23427), X731 = c(0.23719, 0.23696), X732 = c(0.23984,
0.23959), X733 = c(0.24229, 0.24203), X734 = c(0.24452, 0.24426
), X735 = c(0.24668, 0.24638), X736 = c(0.24867, 0.24839),
X737 = c(0.25053, 0.25028), X738 = c(0.25229, 0.25203), X739 = c(0.25382,
0.25359), X740 = c(0.25531, 0.25508), X741 = c(0.25672, 0.25646
), X742 = c(0.25791, 0.25766), X743 = c(0.25907, 0.25884),
X744 = c(0.26014, 0.25993), X745 = c(0.2611, 0.26089), X746 = c(0.26201,
0.26178), X747 = c(0.26278, 0.26257), X748 = c(0.26347, 0.26329
), X749 = c(0.26414, 0.26397), X750 = c(0.26475, 0.26459),
X751 = c(0.26525, 0.2651), X752 = c(0.26568, 0.26554), X753 = c(0.26614,
0.266), X754 = c(0.26652, 0.26639), X755 = c(0.26682, 0.26671
), X756 = c(0.2671, 0.26701), X757 = c(0.26743, 0.26734),
X758 = c(0.26767, 0.26758), X759 = c(0.26789, 0.26781), X760 = c(0.26814,
0.26808), X761 = c(0.2682, 0.26817), X762 = c(0.26835, 0.26831
), X763 = c(0.26856, 0.26851), X764 = c(0.26872, 0.26869),
X765 = c(0.26884, 0.26881), X766 = c(0.26892, 0.2689), X767 = c(0.26896,
0.26894), X768 = c(0.26898, 0.26896), X769 = c(0.2691, 0.26909
), X770 = c(0.2692, 0.2692), X771 = c(0.26921, 0.26921),
X772 = c(0.26923, 0.26926), X773 = c(0.26927, 0.26931), X774 = c(0.26935,
0.26939), X775 = c(0.26945, 0.26947), X776 = c(0.26946, 0.26949
), X777 = c(0.26948, 0.26952), X778 = c(0.26953, 0.26958),
X779 = c(0.26958, 0.26963), X780 = c(0.26965, 0.2697), X781 = c(0.2697,
0.26975), X782 = c(0.2697, 0.26977), X783 = c(0.26972, 0.26978
), X784 = c(0.26979, 0.26982), X785 = c(0.26987, 0.2699),
X786 = c(0.26991, 0.26998), X787 = c(0.26989, 0.26997), X788 = c(0.26991,
0.26998)), .Names = c("Sample", "plantType", "plantCondition",
"REPI", "X638", "X639", "X640", "X641", "X642", "X643", "X644",
"X645", "X646", "X647", "X648", "X649", "X650", "X651", "X652",
"X653", "X654", "X655", "X656", "X657", "X658", "X659", "X660",
"X661", "X662", "X663", "X664", "X665", "X666", "X667", "X668",
"X669", "X670", "X671", "X672", "X673", "X674", "X675", "X676",
"X677", "X678", "X679", "X680", "X681", "X682", "X683", "X684",
"X685", "X686", "X687", "X688", "X689", "X690", "X691", "X692",
"X693", "X694", "X695", "X696", "X697", "X698", "X699", "X700",
"X701", "X702", "X703", "X704", "X705", "X706", "X707", "X708",
"X709", "X710", "X711", "X712", "X713", "X714", "X715", "X716",
"X717", "X718", "X719", "X720", "X721", "X722", "X723", "X724",
"X725", "X726", "X727", "X728", "X729", "X730", "X731", "X732",
"X733", "X734", "X735", "X736", "X737", "X738", "X739", "X740",
"X741", "X742", "X743", "X744", "X745", "X746", "X747", "X748",
"X749", "X750", "X751", "X752", "X753", "X754", "X755", "X756",
"X757", "X758", "X759", "X760", "X761", "X762", "X763", "X764",
"X765", "X766", "X767", "X768", "X769", "X770", "X771", "X772",
"X773", "X774", "X775", "X776", "X777", "X778", "X779", "X780",
"X781", "X782", "X783", "X784", "X785", "X786", "X787", "X788"
), row.names = 1:2, class = "data.frame")
你可以试试这个
spec.data$REPI <- apply(spec.data[,-(1:4)], 1, function(x) which.max(diff(x)))
或者您可以尝试使用 dplyr 和 tidyr:
library(dplyr)
library(tidyr)
spec.data %>%
gather(key, value, -Sample, -plantType, - plantCondition, -REPI) %>%
group_by(Sample) %>%
summarise(which.max(diff(value)))
他们似乎给出了相同的结果。