I’ve run into a problem, as I cannot get a proper working LINQ statement here.
Suppose I have a DataTable with x rows and I have to sort based on the sum of the Quantity column. Then I have a condition Requested Quantity = 20. I need to find the rows equal to the exact sum of RequestedQuantity, but only where the combination of 3 rows is equal to it.
+-----+----------+
| Bin | Quantity |
+-----+----------+
| 1 | 10 |
| 2 | 5 |
| 3 | 5 |
| 4 | 10 |
| 5 | 15 |
+-----+----------+
I can’t seem to figure out the proper LINQ syntax to get this to work. My starting point is this:
From row In StorageBins.AsEnumerable.GroupBy( _
Convert.ToDouble(Function (x) x("Quantity"), cultureInfo)).Sum( _
Function (y) Convert.ToDouble(y("Quantity"), cultureInfo) = _
Double.Parse(RequestedQuantity,cultureInfo))
Initially, I am just trying to get any rows that are equal to my condition. My end-goal, however, is getting any three rows that exactly sum up to my Requested quantity.
I’m not an expert in LINQ, unfortunately. I hope some of you might be!
Maybe I'm missing something, but this actually seems like a pretty complicated problem. Pick any 3 records, but only 3, that add up to exactly 20. How many rows are there in the database? Because this could get to be quite a few potential combinations pretty quickly. And what do you do after you get the 3? Do you have to go back through recursively and group up the other records as well? Or you just need the first set of 3 that add up to 20?
Assuming you just need the first 3, I would do something like this:
Get the first record that is less that 20. Remove it from your input list and put it into your target set.
Then get the first record that is less than 20 minus the first value. ie if the first value was a '5', get records that are less than 15 (20 minus 5). This ensures you 'leave room' for the third value. Remove it from the original list and into your target set.
Then get the first record that is exactly 20 minus number one minus number two. Remove it from the input list and into the target set.
Now you would have to do this in iterators. If there is no value that meets the third criterion, release the third value from your target set and put it back in your input list. Then go back to step 2 and pick the next record that matches step 2 (and ideally that is not equal to the previous value). And if you exhaust all of the iterations through step 2, go back to step one and pick the next value there, and start the whole thing over again...
Unless I'm misunderstanding your requirement...
i am trying to read a csv file and my code is as follows
param=csvRead("C:\Users\USER\Dropbox\VOA-BK code\assets\Iris.csv",",","%i",'double',[],[],[1 2 3 4]); //reads number of clusters and features
data=csvRead("C:\Users\USER\Dropbox\VOA-BK code\assets\Iris.csv",",","%f",'double',[],[],[3 1 19 4]); //reads the values
numft=param(1,1);//save number of features
numcl=param(2,1);//save number of clusters
data_pts=0;
data_pts = max(size(data, "r"));//checks how many number of rows
disp(data(numft-3:data_pts,:));//print all data points (I added -3 otherwise it displays only 15 rows)
disp(numft);//print features
disp(data_pts);//print features
disp(param);
endfunction
below is the values that i am trying to read
features,4,,
clusters,3,,
5.1,3.5,1.4,0.2
4.9,3,1.4,0.2
4.7,3.2,1.3,0.2
4.6,3.1,1.5,0.2
5,3.6,1.4,0.2
7,3.2,4.7,1.4
6.4,3.2,4.5,1.5
6.9,3.1,4.9,1.5
5.5,2.3,4,1.3
6.5,2.8,4.6,1.5
5.7,2.8,4.5,1.3
6.3,3.3,6,2.5
5.8,2.7,5.1,1.9
7.1,3,5.9,2.1
6.3,2.9,5.6,1.8
6.5,3,5.8,2.2
7.6,3,6.6,2.1
I do not know why the code only displays 15 rows instead of 17. The only time it displays the correct matrix is when i put -3 in numft but with that, the number of columns would be 1. I am so confused. Is there a better way to read the values?
In the csvRead call in the first line of your script the boundaries of the region to read is incorrect, it should be corrected like this:
param=csvRead("C:\Users\USER\Dropbox\VOA-BK code\assets\Iris.csv",",","%i",'double',[],[],[1 2 2 2]);
Using Pentaho PDI 8.3.
After REST calls with quite complex data structures, I was able to extract data with a row for each data element in a REST result/ E.g:
DataCenterClusterAbstract
1
UK1
Datacenter (auto generated)
Company
29
0
39
15
DATAUPDATEJOB
2016-04-09T21:34:31.18
DataCenterClusterAbstract
2
UK1_Murex
Datacenter (auto generated)
Company
0
0
0
0
DATAUPDATEJOB
2016-04-09T21:34:31.18
DataCenterClusterAbstract
3
UK1_UNIX
Notice that there are 8 data elements that are spread out into separate rows. I would like to condense these 8 data elements into one row each iteration in Pentaho. Is this possible? And assign field names?
Row flattener
Condense 8 data element in columns into one row. Each of these 8 data elements are repeating.
(1) Add row flattener
(2) Assign field names for the rows coming in - so you have 10 data attributes in rows specify a field name for each row.
(3) In table output use space as seperator
To set the scene, what I define as identical rows are when the combination of destination and vehicle_brand are the same. For instance in the figure below,
SQL table name: cardriven
rows 2 and 3 are "identical" because of the Dallas-Toyota "combination." Now I want to only display the row with the higher request_id. So for example, between rows 2 and 3, row 3 would get displayed and row 2 would be hidden/removed because 169 > 100. So in the end, only rows 3, 4, 5, 7, and 8 will show and rows 1, 2, 6, and 9 would get hidden/removed.
Hopefully you understand what I am going for here but if you have any questions, please let me know. This will be written in SQL code.
Another problem: I added a new column for dates and entered some random ones for rows 2-4. Row 2 is 12/1/17, row 3 is 11/5/2016, and row 4 is 7/6/2017. Note that row 3 has the highest request_id out of the Dallas-Toyota combination. I decided to enter a new entry in with a request_id = 501 and entry of Dallas, Toyota, and 12/22/2017. After running the program, for Dallas-Toyota I return row 3 but with request_id = 501! It SHOULD return the entry I just entered.
You can use Group By and the Max function to get the highest value.
SELECT MAX(request_id), destination, vehicle_brand
FROM cardriven
GROUP BY destination, vehicle_brand
I have the following Expression in a field in SSRS:
=iif(Fields!Score.Value > Previous(Fields!Score.Value),"Greater","Less Than")
I have the following Scores in my scenario across 4 rows:
3
3
4
5
It results in:
3 - Greater
3 - Less Than
4 - Greater
5 - Greater
The issue is with the first row always being Greater. It should be blank because there isn't a previous row to compare against. I would expect the results to be as follows:
3 -
3 - Same
4 - Greater
5 - Greater
How could I change the above formula to produce the above result?
The above is an example of only one row group. There are then further row groups with different Scores, so the different results of Same/Greater/Less Than need to work across the different row groups.
Try following:
=IIF(RowNumber(NOTHING)=1,"",IIF(Fields!Score.Value = Previous(Fields!Score.Value),"Same",IIF(Fields!Score.Value > Previous(Fields!Score.Value),"Greater","Less Than")))
modified. try now.