我在数据框中有一个字符字段，其中包含数字，例如（0.5,3.5,7.8,2.4）。
对于每个记录，我试图从字符串中提取最大值并将其放入新列中。
e.g。
SwipeRefreshLayout所需的输出是：
x csi
1 0.5, 6.7, 2.3
2 9.5, 2.6, 1.1
3 0.7, 2.3, 5.1
4 4.1, 2.7, 4.7
我已经进行了各种尝试......我的最新尝试是以下内容 - 它提供了整个列的最大csi分数，而不是单个行的csi数字......
x csi csi_max
1 0.5, 6.7, 2.3 6.7
2 9.5, 2.6, 1.1 9.5
3 0.7, 2.3, 5.1 5.1
4 4.1, 2.7, 4.7 4.7
谢谢
答案 0 :(得分：6)
我们可以使用base R
data.frame或者，在分离出“csi”后，可以使用read.table中的df1$csi_max <- do.call(pmax, read.table(text=df1$csi, sep=","))
来完成此操作。列FlatCheckBox.Checked与FlatCheckBox.Unchecked
<UserControl x:Name="userControl" x:Class="Sync_Launcher.Controls.FlatCheckBox"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:controls="clr-namespace:Sync_Launcher.Controls"
mc:Ignorable="d"
d:DesignHeight="30"
Background="Transparent" MouseLeftButtonDown="FlatCheckBox_OnMouseLeftButtonDown">
<Grid SnapsToDevicePixels="True">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="{Binding ActualHeight, ElementName=userControl}"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid Column="0">
<Grid Name="tickHolderGridRoot" Margin="4">
<Grid.LayoutTransform>
<TransformGroup>
<RotateTransform x:Name="rotationTransform" Angle="0"/>
</TransformGroup>
</Grid.LayoutTransform>
<Grid Name="tickHolderGrid" Margin="0,0">
<Border Name="tickBorder" SnapsToDevicePixels="True" Opacity="0" BorderThickness="2,0,0,2" BorderBrush="#FF1CA36F" />
<Border Name="overlayBorder" SnapsToDevicePixels="True" Opacity="1" BorderThickness="2,2,2,2" BorderBrush="#FF404D61" />
</Grid>
</Grid>
</Grid>
<Label
Grid.Column="1"
Content="{Binding Text, ElementName=userControl}"
VerticalContentAlignment="Center"
FontSize="16"
Padding="5,0"
FontStyle="{Binding FontStyle, ElementName=userControl}"
FontWeight="{Binding FontWeight, ElementName=userControl}"/>
</Grid>
<UserControl.Resources>
<Duration x:Key="animationDuration">0:0:0.4</Duration>
<KeyTime x:Key="animationEnd">0:0:0.4</KeyTime>
</UserControl.Resources>
<UserControl.Triggers>
<EventTrigger SourceName="userControl" RoutedEvent="controls:FlatCheckBox.Checked">
<BeginStoryboard>
<Storyboard Timeline.DesiredFrameRate="60">
<DoubleAnimationUsingKeyFrames Storyboard.TargetName="rotationTransform" Storyboard.TargetProperty="Angle" Duration="{StaticResource animationDuration}">
<EasingDoubleKeyFrame KeyTime="0" Value="0"/>
<EasingDoubleKeyFrame KeyTime="{StaticResource animationEnd}" Value="-60">
<EasingDoubleKeyFrame.EasingFunction>
<CircleEase EasingMode="EaseOut"/>
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimation Storyboard.TargetName="overlayBorder" Storyboard.TargetProperty="Opacity" From="1" To="0" Duration="{StaticResource animationDuration}"/>
<DoubleAnimation Storyboard.TargetName="tickBorder" Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="{StaticResource animationDuration}"/>
<ThicknessAnimation Storyboard.TargetName="tickHolderGrid" Storyboard.TargetProperty="Margin" From="0,0" To="0,2" Duration="{StaticResource animationDuration}"/>
<ThicknessAnimation Storyboard.TargetName="tickHolderGridRoot" Storyboard.TargetProperty="Margin" From="4" To="2,0,2,4" Duration="{StaticResource animationDuration}"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
<EventTrigger SourceName="userControl" RoutedEvent="controls:FlatCheckBox.Unchecked">
<BeginStoryboard>
<Storyboard>
<DoubleAnimationUsingKeyFrames Storyboard.TargetName="rotationTransform" Storyboard.TargetProperty="Angle" Duration="{StaticResource animationDuration}">
<EasingDoubleKeyFrame KeyTime="0" Value="-60"/>
<EasingDoubleKeyFrame KeyTime="{StaticResource animationEnd}" Value="0">
<EasingDoubleKeyFrame.EasingFunction>
<CircleEase EasingMode="EaseOut"/>
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimation Storyboard.TargetName="overlayBorder" Storyboard.TargetProperty="Opacity" From="0" To="1" Duration="{StaticResource animationDuration}"/>
<DoubleAnimation Storyboard.TargetName="tickBorder" Storyboard.TargetProperty="Opacity" From="1" To="0" Duration="{StaticResource animationDuration}"/>
<ThicknessAnimation Storyboard.TargetName="tickHolderGrid" Storyboard.TargetProperty="Margin" From="0,2" To="0,0" Duration="{StaticResource animationDuration}"/>
<ThicknessAnimation Storyboard.TargetName="tickHolderGridRoot" Storyboard.TargetProperty="Margin" From="2" To="4" Duration="{StaticResource animationDuration}"/>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</UserControl.Triggers>
答案 1 :(得分：3)
希望这有帮助！
df$csi_max <- sapply(df$csi, function(x) max(as.numeric(unlist(strsplit(as.character(x), split=",")))))
输出是：
x csi csi_max
1 1 0.5, 6.7, 2.3 6.7
2 2 9.5, 2.6, 1.1 9.5
3 3 0.7, 2.3, 5.1 5.1
4 4 4.1, 2.7, 4.7 4.7
#sample data
> dput(df)
structure(list(x = 1:4, csi = structure(c(1L, 4L, 2L, 3L), .Label = c("0.5, 6.7, 2.3",
"0.7, 2.3, 5.1", "4.1, 2.7, 4.7", "9.5, 2.6, 1.1"), class = "factor")), .Names = c("x",
"csi"), class = "data.frame", row.names = c(NA, -4L))
修改
正如@RichScriven所建议的那样，效率更高的方式可能是
df$csi_max <- sapply(strsplit(as.character(df$csi), ","), function(x) max(as.numeric(x)))
答案 2 :(得分：1)
使用splitstackshape包的解决方案。
library(splitstackshape)
dat$csi_max <- apply(cSplit(dat, "csi")[, -1], 1, max)
dat
# x csi csi_max
# 1 1 0.5, 6.7, 2.3 6.7
# 2 2 9.5, 2.6, 1.1 9.5
# 3 3 0.7, 2.3, 5.1 5.1
# 4 4 4.1, 2.7, 4.7 4.7
数据
dat <- read.table(text = "x csi
1 '0.5, 6.7, 2.3'
2 '9.5, 2.6, 1.1'
3 '0.7, 2.3, 5.1'
4 '4.1, 2.7, 4.7'",
header = TRUE, stringsAsFactors = FALSE)