I got a dataset with Temperature values for different cities. For the visualisation of these values i'm using ngx-charts.
The dataset contains subsets for munich, berlin and stuttgart. Is it possible hide a certain subset when clicking on it ?
For example the three sets are plotted using a line chart. Selecting stuttgart hides stuttgart, so that only munich and berlin are displayed.
The chart emits click events, so you can modify your data based on that.
In your template, use the select output from the chart:
<ngx-charts-line-chart
[results]="data"
(select)="select($event)">
</ngx-charts-line-chart>
In your component, implement the select method:
select(item) {
console.log('Item clicked', item);
// filter your data object here based on the data in item
this.data = [...this.data.filter(i => {
return i.name !== item.series;
})]
}
Related
Is there a Vega/Vega-lite equivalent of pandas' df.columns?
I would like to get an array with all column names in Vega-lite. For this dataset:
{"data": { "values" : [{"a":4, "b":5},{"a":6, "b":7}] }}
I would like to get an array ["a","b"]. This would be extremely helpful when using the fold transform with large datasets.
Here is one way to get a Vega dataset fieldnames using Vega API.
In Vega spec, add signal declaration, e.g.:
"signals":[
{"name": "signal_data_table_fieldnames"
}
In javacript, use Vega view API methods signal and data to retrieve the first record of the dataset table and obtain the fieldnames as an array with javascript Object.keys()
When using the view.signal, the Vega API method can both get and set the internal Vega signal value. The updated signal value can be used anywhere within the Vega spec.
Vega API docs for signal and data methods:
https://vega.github.io/vega/docs/signals/
https://vega.github.io/vega/docs/api/view/#signals
https://vega.github.io/vega/docs/api/view/#data-and-scales
Example code using
https://vega.github.io/vega/usage/
with bar chart example
https://vega.github.io/vega/examples/bar-chart/ :
var view;
fetch('https://vega.github.io/vega/examples/bar-chart.vg.json')
.then(res => res.json())
.then(spec => render(spec))
.catch(err => console.error(err));
function render(spec) {
view = new vega.View(vega.parse(spec), {
renderer: 'canvas', // renderer (canvas or svg)
container: '#view', // parent DOM container
hover: true // enable hover processing
});
return view.runAsync();
}
// Vega API
view.signal("signal_data_table_fieldnames", Object.keys(view.data("table")[0]));
console.log(view.signal("signal_data_table_fieldnames"));
I use vue-chartjs to draw some chart like line, bar, etc.
In my project, there are many cases using specific value or lable of data in chart.
Using tooltip option of vue-chartjs, I can check that value or label of data item when hovered.
I want to know how to access or get information of specific data matched with point on graph when clicked(not hovered).
Here is my code about chart options.
chartOptions: {
responsive: false,
onClick: function(evt){
//Some logic to get value of label of specific data...(type, label, value, ...)
}
In my case, I use 'onclick' option to access specific data on point triggered 'click' event. In 'onClick' callback, I checked all of chart elements and dataset, etc.
How can I get value of label specific dataItem on point of graph(like line) or bar of graph(like bar) when triggered click event?
I was not able to find a solution that worked for me, but I dug a little bit and this is what I came up with.
onClick: function(evt, array) {
if (array.length != 0) {
var position = array[0]._index;
var activeElement = this.tooltip._data.datasets[0].data[position]
console.log(activeElement);
} else {
console.log("You selected the background!");
}
}
This will get the position in the array that you clicked and grab the data from what position you clicked. This may not be the prettiest or best example, but it worked for me.
This solution use the getElementAtEvent method of chartjs, but to use that you need reference to the Chart itself, not the Vue component. We can get that from the $data._chart property. To use this in a parent Vue component, we use the $refs as seen below`.
So parent defines the chart options
{
...
options: {
onClick: this.handleChartClick
}
...
}
and then parent method, using $refs with $data._chart to get the chart. We get the datasetIndex and value and also the tooltip
handleChartClick(evt, elements) {
var chart = this.$refs.periodChart.$data._chart;
const chartIndex = chart.getElementAtEvent(evt);
if (chartIndex.length !== 0) {
const datasetIndex = chartIndex[0]._datasetIndex;
const position = chartIndex[0]._index;
const info = {
datasetIndex: datasetIndex,
valueIndex: position,
label: chart.tooltip._data.labels[position],
value: chart.tooltip._data.datasets[datasetIndex].data[position]
};
console.log(info);
} else {
console.log("Background clicked");
}
I am using EXTJS 4.2.1 and my application has a grid including paging, the grouping summary and the summary feature. I want to override the sum of the summary feature, because it should display the grand total sum of the whole data set and not only for the current displayed page.
Is that possible to override the summary feature to do so?
Thanky you very much for every advice in advance. :-)
Use summaryRenderer in column configuration. It is an undocummented feature of ExtJS allowing you to show custom data in your summary row.
You will have to summarize the data server-side and send them to client where you will access it in the summaryRenderer.
Like so:
columns: {
items: [
{
text: "Column A",
dataIndex: "field_A",
summaryRenderer: function( value, summaryData, dataIndex ) {
var grid = this;
// Get the value here and return it
var result = functionToGetValue( grid );
return result;
}
},
// ...
}
]
The functionToGetValue is the place where you pass the summarization value you sent to your client from server.
How you do that depens on your code. You have access to store via grid.getStore().
It is possible to add the summary data to each record and then simply use store.getAt(0).get( 'summaryValue' ), it is kind of wasteful, but it is simple and it works.
I am using slick grid to show JSON data.
On external button click i want highlight specific row based on column values.
Such as highlight row which have cost=75 and venue_id =87 and Impression=268
Got solution :
dataView.getItemMetadata = function (row) {
var item = dataView.getItem(row);
if (item["" + columnName+ ""] == colValue)
{
return { cssClasses: 'highlight' };
}
return null;
}
grid = new Slick.Grid("#myGrid", dataView, myColList, options);
The other suggested option seems to be have heavy load on my system, as my system have thousand of records and a particular row have to highlighted and suggested solution kind of refreshes the whole table. For some reasons it is not working for me.
I got around this by using Slickgrid's flashCell. Even no need of getItemMetadata()
var rowId=dataView.getRowById(idvalue);//id of the row to be highlighted, as slickgrid enforced an id field
grid.scrollRowToTop(rowId);//makes the row visible
grid.getColumns().forEach(function(col){//get all the columns
grid.flashCell(rowId, grid.getColumnIndex(col.id));//flash it
})
Hope this helps to coming to this page for the answer.
how to select data of single column from a grid data.
The grid data is passed as following:
var url = "/Main/Grid?tbname="+parameter;
var jsonp = new $.ig.JSONPDataSource({
dataSource: url, paging: {
enabled: true, pageSize: 10,
type: "remote"
}
});
$("#listingGrid").igGrid("dataSourceObject", jsonp).igGrid("dataBind");
I have to retrieve data in another page from this grid and select one column from this data.
and i have retrieved data like this
var ds = window.parent.$("#listingGrid").igGrid("option", "dataSource");
but not able to access one column data.
I'm assuming that since you are using the DataSource directly that you don't want the actual columns in the grid, which might differ from the columns in the data source depending on how you have the grid set up.
The easiest way to go about this would probably be to call the data function off of the data source once you retrieve it from your other page. This function returns an array of objects that are the items in each row. Once you have that you can iterate over each of the items and query the individual property.
var ds = window.parent.$('#listingGrid').igGrid('option', 'dataSource');
$.each(ds.data(), function (i, item) {
var itemProperty = item.Property;
// ...
});
You'll need to make sure that the data is all loaded from the service first though or data will possibly return an empty array.