我想在R中完成以下操作:我同样用于循环,我想将不同的图保存到不同的jpeg文件中。我的问题是我不确切地知道如何告诉R"将此情节保存在这个开放的jpeg文件中以及此其他 jpeg中的其他情节文件"
我目前可以使用两个for循环来执行此操作:
const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2})
constructor(props) {
super(props)
this.state = {
favoriteDB: props.favorites,
renderPlaceholder: true,
dataSource: ds.cloneWithRows([])
}
}
componentDidMount() {
InteractionManager.runAfterInteractions(() => {
this.setState({
dataSource: ds.cloneWithRows(this.state.favoriteDB),
renderPlaceholder: false
})
})
}
componentWillReceiveProps(prevProps) {
const {favorites} = this.props
if (JSON.stringify(favorites) != JSON.stringify(prevProps.favorites)) {
this._updateFavorites()
}
}
_updateFavorites() {
const {favorites} = this.props
this.setState({
favoriteDB: favorites,
dataSource: ds.cloneWithRows(favorites)
})
}
render() {
const {dataSource} = this.state
const {visibleHeight, visibleWidth} = this.props
if (this.state.renderPlaceholder)
return <Placeholder/>
return (
<Container theme={theme}>
<View style={{ flex:1, height: visibleHeight - 100, width: visibleWidth }}>
<Row>
<Col>
<List>
<ListView
style={{ height: visibleHeight - 100, width: visibleWidth }}
enableEmptySections={TRUE}
automaticallyAdjustContentInsets={FALSE}
initialListSize={100}
pageSize={100}
dataSource={dataSource}
renderRow={rowData => this._renderRow(rowData)}/>
</List>
</Col>
</Row>
</View>
</Container>
)
}
但是,我想将这两个循环组合在一起(后面的内容不是实际的代码,而是我想要完成的想法):
library(data.table)
set.seed(10)
data1 <- data.table(A = letters[3:5], B = letters[6:8],
C = rnorm(20), D = rnorm (20) )
for( i in unique(data1$A )){
data2 <- data1[A == i]
jpeg(paste(i,'plot1.jpg',sep = ''))
hist(data2$C)
dev.off()
}
for( i in unique(data1$A )){
data2 <- data1[A == i]
jpeg(paste(i,'plot2.jpg',sep = ''))
hist(data2$D)
dev.off()
}
答案 0 :(得分:2)
library(data.table)
set.seed(10)
data1 <- data.table(A = letters[3:5], B = letters[6:8],
C = rnorm(20), D = rnorm (20) )
for( i in unique(data1$A )){
data2 <- data1[A == i]
jpeg(paste(i,'plot1.jpg',sep = ''))
hist(data2$C)
dev.off()
jpeg(paste(i,'plot2.jpg',sep = ''))
hist(data2$D)
dev.off()
}