本文介绍了在浮点间隔上出现意外行为[已解决]的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

这里是一个例子,其中 foverlaps(...)似乎找到不重叠的匹配。谁可以帮助我理解我在做什么?

Here is an example where foverlaps(...) seems to be finding matches that do not overlap. Can anyone help me understand what I'm doing wrong?

似乎是使用 foverlaps(...)在data.table包中。下面的数据集来自该文章。

The problem in this post seems like an excellent opportunity to use foverlaps(...) in the data.table package. The datasets below are from that post.

dinosaurs <- structure(list(GENUS = structure(1:3, .Label = c("Abydosaurus", "Achelousaurus", "Acheroraptor"), class = "factor"), ma_max = c(109, 84.9, 70.6), ma_min = c(94.3, 70.6, 66.043), ma_mid = c(101.65, 77.75, 68.3215)), .Names = c("GENUS", "ma_max", "ma_min", "ma_mid"), class = "data.frame", row.names = c(NA, -3L))
stages    <- structure(list(Stage = structure(c(13L, 19L, 17L, 21L, 1L, 4L, 6L, 8L, 16L, 14L, 20L, 7L, 23L, 12L, 5L, 3L, 2L, 10L, 22L, 11L, 18L, 9L, 15L), .Label = c("Aalenian", "Albian", "Aptian", "Bajocian", "Barremian", "Bathonian", "Berriasian", "Callovian", "Campanian", "Cenomanian", "Coniacian", "Hauterivian", "Hettangian", "Kimmeridgian", "Maastrichtian", "Oxfordian", "Pliensbachian", "Santonian", "Sinemurian", "Tithonian", "Toarcian", "Turonian", "Valanginian"), class = "factor"),ma_max = c(201.6, 197, 190, 183, 176, 172, 168, 165, 161, 156, 151, 145.5, 140, 136, 130, 125, 112, 99.6, 93.5, 89.3, 85.8, 83.5, 70.6), ma_min = c(197, 190, 183, 176, 172, 168, 165, 161, 156, 151, 145.5, 140, 136, 130, 125, 112, 99.6, 93.5, 89.3, 85.8, 83.5, 70.6, 66.5), ma_mid = c(199.3, 193.5, 186.5, 179.5, 174, 170, 166.5, 163, 158.5, 153.5, 148.25, 142.75, 138, 133, 127.5, 118.5, 105.8, 96.55, 91.4, 87.55, 84.65, 77.05, 68.05)), .Names = c("Stage", "ma_max", "ma_min", "ma_mid"), class = "data.frame", row.names = c(NA, -23L))
dinosaurs
#           GENUS ma_max ma_min   ma_mid
# 1   Abydosaurus  109.0 94.300 101.6500
# 2 Achelousaurus   84.9 70.600  77.7500
# 3  Acheroraptor   70.6 66.043  68.3215
head(stages)
#           Stage ma_max ma_min ma_mid
# 1    Hettangian  201.6    197  199.3
# 2    Sinemurian  197.0    190  193.5
# 3 Pliensbachian  190.0    183  186.5
# 4      Toarcian  183.0    176  179.5
# 5      Aalenian  176.0    172  174.0
# 6      Bajocian  172.0    168  170.0

目标是找出在每个地质阶段存在的恐龙属的数量。

The goal is to find the number of dinosaur genera which were present in each geological stage.

library(data.table)   # 1.9.4
setDT(dinosaurs)[,ma_mid:=NULL]
setDT(stages)[,ma_mid:=NULL]
setkey(dinosaurs,ma_min,ma_max)
foverlaps(stages,dinosaurs,type="any",nomatch=0)
#            GENUS ma_max ma_min         Stage i.ma_max i.ma_min
# 1:   Abydosaurus  109.0 94.300        Albian    112.0     99.6
# 2:   Abydosaurus  109.0 94.300    Cenomanian     99.6     93.5
# 3: Achelousaurus   84.9 70.600     Coniacian     89.3     85.8
# 4: Achelousaurus   84.9 70.600     Santonian     85.8     83.5
# 5:  Acheroraptor   70.6 66.043     Campanian     83.5     70.6
# 6: Achelousaurus   84.9 70.600     Campanian     83.5     70.6
# 7:  Acheroraptor   70.6 66.043 Maastrichtian     70.6     66.5
# 8: Achelousaurus   84.9 70.600 Maastrichtian     70.6     66.5

这是大多数正确的,但看看第3行。这似乎断言Cenomanian阶段,从85.8 8930万年前,与Achelousaurus重叠,它生活在70.6到8490万年前。

This is mostly correct, but look at row 3. This seems to assert that the Cenomanian stage, from 85.8 to 89.3 million years ago, overlaps with Achelousaurus, which lived from 70.6 to 84.9 million years ago. What am I missing?

推荐答案

在1.9.5版本中,我得到:

On 1.9.5, I get this:

#            GENUS ma_max ma_min         Stage i.ma_max i.ma_min
# 1:   Abydosaurus  109.0 94.300        Albian    112.0     99.6
# 2:   Abydosaurus  109.0 94.300    Cenomanian     99.6     93.5
# 3: Achelousaurus   84.9 70.600     Santonian     85.8     83.5
# 4:  Acheroraptor   70.6 66.043     Campanian     83.5     70.6
# 5: Achelousaurus   84.9 70.600     Campanian     83.5     70.6
# 6:  Acheroraptor   70.6 66.043 Maastrichtian     70.6     66.5
# 7: Achelousaurus   84.9 70.600 Maastrichtian     70.6     66.5

在中的1.9.5中。如果你也可以验证这一点,会很棒。

Most likely floating point bug fixed in 1.9.5 in this commit. Would be great if you could verify this as well.

这篇关于在浮点间隔上出现意外行为[已解决]的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

08-15 11:40