我有一个如下所示的相关数据集：
V1 V2 R2
1 2 0.4
1 3 0.5
3 5 0.3
我希望将它转换为两列数据，以便在一个y（在列R2中）中有多个x（在列V中）用于散点图。它看起来像这样：
V R2
1 0.4
2 0.4
1 0.5
2 0.5
3 0.5
3 0.3
4 0.3
5 0.3
我怎样才能在R？
中这样做答案 0 :(得分：2)
在tidyverse中，您可以使用app.get('/api/imagesearch/:query', newQuery)
app.post('/', newQuery)
function newQuery (req, res) {
let query = req.body.query || req.params.query
console.log(`Search Query: ${query}`)
res.status(200)
res.set('Content-Type', 'application/json')
// This doesn't work
let searchResults = JSON.stringify(cseSearch(req))
res.end(searchResults)
}
function cseSearch (request) {
let cseParams = '' +
`?q=${request.params.query}` +
`&cx=${process.env.CSE_ID}` +
`&key=${process.env.API_KEY}` +
'&num=10' +
'&safe=high' +
'&searchType=image' +
`&start=${request.query.offset || 1}`
let options = {
hostname: 'www.googleapis.com',
path: '/customsearch/v1' + encodeURI(cseParams)
}
let cseRequest = https.request(options, cseResponse => {
let jsonString = ''
let searchResults = []
cseResponse.on('data', data => {
jsonString += data
})
cseResponse.on('end', () => {
let cseResult = JSON.parse(jsonString)
let items = cseResult.items
items.map(item => {
let resultItem = {
url: item.link,
snippet: item.title,
thumbnail: item.image.thumbnailLink,
context: item.image.contextLink
}
searchResults.push(resultItem)
})
// This doesn't work... wrong scope, two callbacks deep
return searchResults
})
})
cseRequest.on('error', e => {
console.log(e)
})
cseRequest.end()
}
制作所需向量的列表列，以便在每对起点和终点上迭代purrr::map2，然后使用seq展开：< / p>
tidyr::unnest在基数R中，没有简单的等效df <- data.frame(V1 = c(1L, 1L, 3L),
V2 = c(2L, 3L, 5L),
R2 = c(0.4, 0.5, 0.3))
library(tidyverse)
df %>% transmute(V = map2(V1, V2, seq), R2) %>% unnest()
#> R2 V
#> 1 0.4 1
#> 2 0.4 2
#> 3 0.5 1
#> 4 0.5 2
#> 5 0.5 3
#> 6 0.3 3
#> 7 0.3 4
#> 8 0.3 5
，因此更容易使用unnest（多变量Map，大致相当于lapply以上）构建一个数据框列表，其中包含purrr::map2值（由R2回收），然后将data.frame编入单个数据框：
do.call(rbind, ...)查看每种产品的中间产品，以了解它们的工作原理。
答案 1 :(得分：0)
以下是使用public function getCsv()
{
$shipmentIds = $this->getRequest()->getParam('internal_shipment_ids'); // Parameter will be like internal_'checkboxName'
$csv = '';
$this->_isExport = true;
$this->_prepareGrid();
if($shipmentIds)
{
$shipmentIds = explode(',' , $shipmentIds);
$this->getCollection()->addAttributeToFilter('main_table.entity_id', array('in' => $shipmentIds))->getSelect()->limit();
$this->getCollection()->setPageSize(0);
$this->getCollection()->load();
$this->_afterLoadCollection();
}
else
{
$this->getCollection()->getSelect()->limit();
$this->getCollection()->setPageSize(0);
$this->getCollection()->load();
$this->_afterLoadCollection();
}
$data = array();
foreach ($this->_columns as $column) {
if (!$column->getIsSystem()) {
$data[] = '"'.$column->getExportHeader().'"';
}
}
$csv.= implode(',', $data)."\n";
foreach ($this->getCollection() as $item) {
$data = array();
foreach ($this->_columns as $column) {
if (!$column->getIsSystem()) {
$data[] = '"' . str_replace(array('"', '\\'), array('""', '\\\\'),
$column->getRowFieldExport($item)) . '"';
}
}
$csv.= implode(',', $data)."\n";
}
if ($this->getCountTotals())
{
$data = array();
foreach ($this->_columns as $column) {
if (!$column->getIsSystem()) {
$data[] = '"' . str_replace(array('"', '\\'), array('""', '\\\\'),
$column->getRowFieldExport($this->getTotals())) . '"';
}
}
$csv.= implode(',', $data)."\n";
}
return $csv;
}
data.table