I'm stuck with my first dashboard project with d3, dc and crossfilter. Cannot find a solution.
"ETCBTC","BUY","0.002325","1.04","0.00241800","0.00104","ETC"
"ETCBTC","SELL","0.002358","1.04","0.00245232","0.00000245","BTC"
"LTCETH","SELL","0.30239","0.006","0.00181434","0.00000181","ETH"
"LTCETH","SELL","0.30239","0.149","0.04505611","0.00004506","ETH"
I have different trading pairs in first column and from it i need to use only last pair BTC and ETH in this example.
I found the filter that helps me to do that.
The thing is I need to have BTC and ETH in my select menu which can apply filter.
function show_market_selector(ndx) {
var marketDim = ndx.dimension(dc.pluck("Market"));
var selectorMenu = marketDim.group();
function filterItems(query) {
return ndx.dimension(dc.pluck("Market")).filter(function(el) {
return el.toLowerCase().indexOf(query.toLowerCase()) > 0;
});
}
filterItems("BTC");
var select = dc.selectMenu("#market-selector")
.dimension(marketDim)
.group(selectorMenu);
select.title(function (d){
return "BTC";
});
}
Now I get all pair in group in this menu. But my target is just to have BTC and ETH in the select menu.
I hope someone can give me advice. Thank you.
I think it would be easier just to use the currency as your dimension key:
var currencyDim = ndx.dimension(d => d.Market.slice(3)),
currencyGroup = marketDim.group();
var select = dc.selectMenu("#market-selector")
.dimension(currencyDim)
.group(currencyGroup);
You don't really want to create a new dimension every time filterItems is called - dimensions are heavy-weight indices which are intended to be kept around.
The name of dimension.filter() is confusing - it's nothing like JavaScript's Array.prototype.filter(), which returns the matching rows. Instead, it's an imperative function which sets the current filter for that dimension (and changes what all the other dimensions see).
If you need a "from currency" dimension, that would be
var fromCurrencyDim = ndx.dimension(d => d.Market.slice(0,3))
Related
I am trying to learn how to use LINQ to perform a query that yields the same result as this:
SELECT (
SELECT SUM(point)
FROM communitymemberpointfeature
WHERE communitymemberpointfeature.communitymemberid = communitymember.id
) AS points, communitymember.*
FROM communitymember
After browsing around the Internet, I constructed the following statement:
var list = (from pointFeature in communityMemberPointFeatureList
join member in communityMemberList on pointFeature.CommunityMemberId equals member.Id
group pointFeature by new { pointFeature.CommunityMemberId }
into grouping
select new
{
grouping,
points = grouping.Sum(row => row.Point)
}).ToList();
But this yielded a result like
[
{
points:7200,
grouping:[
{Id:1,Point:5000,FeatureId:1,CommunityMemberId:1},
{Id:2,Point:2200,FeatureId:1,CommunityMemberId:1},
],
}
...
]
What I really want is a result set like:
[
{points:7200,CommunityMemberId:1,firstname:'john',lastname:'blah' ....},
...
]
Can someone tell me what I did wrong?
Edit after comment added to the end
I can imagine you have problems translating your SQL into LINQ. When trying to write LINQ statements it is usually a lot easier to start from your requirements, instead of starting from a SQL statement.
It seems to me that you have a table with CommunityMembers. Every CommunityMember has a primary key in property Id.
Furthermore, every CommunityMember has zero or more CommunityMemberPointFeatures, namely those CommunityMemberPointFeatures with a foreign key CommunityMemberId that equals the primary key of the CommunityMember that it belongs to.
For example: CommunityMember [14] has all CommunityMemberPointFeatures that have a value CommunityMemberId equal to 14.
Requirement
If I look at your SQL, it seems to me that you want to query all CommunityMembers, each with the sum of property Point of all CommunityMemberPointFeatures of this CommunityMember.
Whenever you want to query "items with their zero or more subitems", like "Schools with their Students", "Customers with their Orders", "CommunityMembers with their PointFeatures", consider using GroupJoin.
A GroupJoin is in fact a Left Outer Join, followed by a GroupBy to make Groups of the Left item with all its Right items.
var result = dbContext.CommunityMembers // GroupJoin CommunityMembers
.GroupJoin(CommunityMemberPointFeatures, // With CommunityMemberPointFeatures
communityMember => communityMember.Id, // from every CommunityMember take the Id
pointFeature => pointFeature.CommunityMemberId, // from every CommunityMemberPointFeature
// take the CommunityMemberId
// Parameter ResultSelector: take every CommunityMember, with all its matching
// CommunityMemberPointFeatures to make one new object:
(communityMember, pointFeaturesOfThisCommunityMember) => new
{
// Select the communityMember properties that you plan to use:
Id = communityMember.Id,
Name = communityMember.Name,
...
// From the point features of this CommunityMember you only want the sum
// or property Point:
Points = pointFeaturesOfThisCommunityMember
.Select(pointFeature => pointFeature.Point)
.Sum(),
// However, if you want more fields, you can use:
PointFeatures = pointFeaturesOfThisCommunityMember.Select(pointFeature => new
{
Id = pointFeature.Id,
Name = pointFeature.Name,
...
// not needed, you know the value:
// CommunityMemberId = pointFeature.CommunityMemberId,
})
.ToList(),
});
Edit after comment
If you want, you can omit Selecting the values that you plan to use.
// Parameter ResultSelector:
(communityMember, pointFeaturesOfThisCommunityMember) => new
{
CommunityMember = communityMember,
PointFeatures = pointFeaturesOfThisCommunityMember.ToList(),
),
However, I would strongly advise against this. If CommunityMember [14] has a thousand PointFeatures, then every PointFeature will have a foreign key with a value 14. So you are transporting this value 14 1001 times. What a waste of processing power, not to mention all the other fields you plan not to use.
Besides: if you do this you violate against information hiding: whenever your tables changes internally, the result of this function changes. Is that what you want?
I have a data set like
{"parent":"/home","inside":"/files","filename":"type.jar",
"extension":"jar","type":"modified","archive"}
Likewise many there are many rows in the json array. I am using crossfilter to read the data and plot graphs and datatables. the Type in the data set has values "added", "modified" and "deleted".
I want to create a data table like
Extension | Added | Modified | Deleted
where added, modified and deleted will hold the count of the files with the specific extension. Can anyone suggest me a way to do so?
So far I have created a dimension like this:
var extensionType = facts.dimension(function(d) {
return d.extension; });
var extensionTypeGroup=extensionType.group();
and I get a grouped output like this,
{"key":"class","value":424},
{"key":"js","value":176},
{"key":"properties","value":26},
{"key":"jar","value":10},
{"key":"css","value":8},
{"key":"txt","value":6},
{"key":"war","value":4},
{"key":"png","value":4},
{"key":"handlebars","value":4},
{"key":"jar_local","value":2},
{"key":"aar","value":2}
How do I get the separate count of added deleted and modified?
Probably the easiest way to do this is to reduce to an object rather than a single value.
This is covered in the FAQ: How do I reduce multiple values at once? What if rows contain a single value but a different value per row? You probably just needed the right search terms to find it.
Actually it looks like the code from the FAQ will work for you unmodified:
var extensionTypeGroup = extensionType.group().reduce(
function(p, v) { // add
p[v.type] = (p[v.type] || 0) + v.value;
return p;
},
function(p, v) { // remove
p[v.type] -= v.value;
return p;
},
function() { // initial
return {};
});
How to make a group by selecting the specific data with crossfilter.js?
var xf = crossfilter(csv);
var yearAppliedDim = xf.dimension(function(d) {
return d.yearApplied;
});
var apply15 = yearAppliedDim.group().reduceCount(function(d) {return d.yearApplied == 2009 }); //<-it doesn't work.
I want to count how many datas which yearApplied=2009.
Please create a JSFiddle or something similar using example data.
You should get a list of groups counts by year if you change your last line to
yearAppliedDim.group().top(Infinity);
Then find the relevant group (where key is '2009') and you should have your count.
I'm using the LinqToExcel library. Working great so far, except that I need to start the query at a specific row. This is because the excel spreadsheet from the client uses some images and "header" information at the top of the excel file before the data actually starts.
The data itself will be simple to read and is fairly generic, I just need to know how to tell the ExcelQueryFactory to start at a specific row.
I am aware of the WorksheetRange<Company>("B3", "G10") option, but I don't want to specify an ending row, just where to start reading the file.
Using the latest v. of LinqToExcel with C#
I just tried this code and it seemed to work just fine:
var book = new LinqToExcel.ExcelQueryFactory(#"E:\Temporary\Book1.xlsx");
var query =
from row in book.WorksheetRange("A4", "B16384")
select new
{
Name = row["Name"].Cast<string>(),
Age = row["Age"].Cast<int>(),
};
I only got back the rows with data.
I suppose that you already solved this, but maybe for others - looks like you can use
var excel = new ExcelQueryFactory(path);
var allRows = excel.WorksheetNoHeader();
//start from 3rd row (zero-based indexing), length = allRows.Count() or computed range of rows you want
for (int i = 2; i < length; i++)
{
RowNoHeader row = allRows.ElementAtOrDefault(i);
//process the row - access columns as you want - also zero-based indexing
}
Not as simple as specifying some Range("B3", ...), but also the way.
Hope this helps at least somebody ;)
I had tried this, works fine for my scenario.
//get the sheets info
var faceWrksheet = excel.Worksheet(facemechSheetName);
// get the total rows count.
int _faceMechRows = faceWrksheet.Count();
// append with End Range.
var faceMechResult = excel.WorksheetRange<ExcelFaceMech>("A5", "AS" + _faceMechRows.ToString(), SheetName).
Where(i => i.WorkOrder != null).Select(x => x).ToList();
Have you tried WorksheetRange<Company>("B3", "G")
Unforunatly, at this moment and iteration in the LinqToExcel framework, there does not appear to be any way to do this.
To get around this we are requiring the client to have the data to be uploaded in it's own "sheet" within the excel document. The header row at the first row and the data under it. If they want any "meta data" they will need to include this in another sheet. Below is an example from the LinqToExcel documentation on how to query off a specific sheet.
var excel = new ExcelQueryFactory("excelFileName");
var oldCompanies = from c in repo.Worksheet<Company>("US Companies") //worksheet name = 'US Companies'
where c.LaunchDate < new DateTime(1900, 0, 0)
select c;
I have a single table and I need to build a bunch of nested objects based on the single table.
Data:
PointA PointB Month Time Price
1 2 11 11:00 10.99
1 2 12 11:00 9.99
Objects are
POINTS {PointA, PointB, Details}
Details {Month, ExtraDetails}
ExtraDetails {Time, Price}
I want to avoid having loads of loops and if statements, so should be able to use linq to do this. but its beyond my linq experience.
edit: These need grouping aswell
any help would be great.
Thanks
Just tried out a solution:
var nestedObjects = from row in data
select new {row.PointA, row.PointB, Details = new {
row.Month, ExtraDetails = new {
row.Time, row.Price
}
}};
This is assuming that you have already got your data into data.
Group by
If you want to group the Points together, you need 'Group By':
var nestedObjects = from row in data
group row by new { row.PointA, row.PointB } into Points
select new {
Points = Points.Key,
Details = from details in Points
select new { row.Month, ExtraDetails = new {
row.Time, row.Price
}}
};
A little more complicated - of course you might want to group by month as well, in which case, you need to follow the same pattern as for the Points bit. Note, this will not create tables, because the group by doesn't quite do that, but it at least creates the structure for you.
Assuming you got your classes defined for the objects you mentioned, and you have a constructor or properties so you can propery create the object in one line you could have a LINQ query returning a list of a POINTS.
If would go something lik this :
var res =
from item in table.AsEnumerable()
select new Points(){PointA = item["PointA"];
PointB = item["PointB"];
Details = from item2 in table.AsEnumberable()
where item["PointA"] = item2["PointA"] and item["PointB"] = item2["PointB"]
select new Details(){
month=item2["month"],
extraDetails = from item3 in table.AsEnumerable()...
}
};
At the end res will be a IEnumerable of Points
I am sorry for the code, I am not at a computer with .NET 3.5 so I cannot write a proper testable query