MDX - StrToMember in Range - format

I'm quite newbie using MDX, I use it in Power BI in order to create different reports.
I'm actually stuck with an issue after a lot of research in different pages, related to Time Ranges.
In the Cube there is a dimension [Time].[Date].[Date], that goes from 2014 to 2020, so I figure out after many hours that all the options using Current Member wouldn't work.
I need to capture a Measure in the last 7, 30, 60, 90 days.
I found two options:
OPTION 1. Using WITH and Member:
`WITH MEMBER [Measures].x AS SUM
({[Time].[Date].&[20190216]:[Time].[Date].&[20190222])
},[Measures].[Avg Loaned])
SELECT NON EMPTY {[Measures].x} on 0
,NON EMPTY ([Time].[Date].[Date]) on 1
FROM [MYCUBE]
WHERE (Some Conditions...)`
OPTION 2. Using WITH, Range and Member
`WITH
SET [Range] AS
{[Time].[Date].&[20190216]:[Time].[Date].&[20190222]}
MEMBER [Measures].x AS SUM
({nonempty([Range]*[Measures].[Avg Loaned])})
SELECT NON EMPTY {[Measures].x} on 0
,NON EMPTY ([Time].[Date].[Date]) on 1
FROM [MYCUBE]
WHERE (Some Conditions...)`
In both cases I get the correct results, and it seems to keep working if I replace
**[Time].[Date].&[20190222]** --> StrToMember("[Time].[Date].&[" + Format(Now(), "YYYYMMDD") + "]")
But it doesn't work when I replace the first date
**[Time].[Date].&[20190216]** --> StrToMember('[Time].[Date].&[' + Format(dateadd('d',-7,Now()), 'YYYYMMDD') + "]")
OR
**[Time].[Date].&[20190216]** --> StrToMember('[Time].[Date].&[' + Format(dateadd('d',-7,cdate(Now())), 'YYYYMMDD') + "]")
OR
**[Time].[Date].&[20190216]** --> StrToMember('[Time].[Date].&[' + Format(cstr(dateadd('d',-7,Now())), 'YYYYMMDD') + "]")
I'm not sure what's the best way to accomplish the task, OPTION 1 or 2, but the main roadblock is how I'm writting down the starting limit for the range trying to use dateadd.
Thanks in advance, I know that there are many posts about this, I tried to adapt the examples to my code but I failed and after some days I'm not sure what could be the issue.
Rgds
Pablo

In your working example you have StrToMember(" and in non-working example you have StrToMember(', so probably you should use double quotes and not single quotes: StrToMember("[Time].[Date].&["...

Related

In Visual FoxPro, how does one incorporate a SUM REST command into a SCAN loop?

I am trying to complete a mortality table, using loops in Visual Foxpro. I have run into one difficulty where the math operation involves doing a sum of of all data in a column for the remaining rows - this needs to be incorporated into a loop. The strategy I thought would work, nesting a SUM REST function into the SCAN REST function, was not successful, and I haven't found a good alternative approach.
In FoxPro, I can successfully use the SCAN function as follows, say:
Go 1
Replace survivors WITH 1000000
SCATTER NAME oprev
SKIP
SCAN rest
replace survivors WITH (1 - oprev.prob) * oprev.survivors
SCATTER NAME oprev
ENDSCAN
(to take the mortality rates in a table and use it to compute number of survivors at each age)
Or, say:
Replace Yearslived WITH 0
SCATTER NAME oprev1
SKIP
SCAN rest
replace Yearslived WITH (oprev1.survivors + survivors) * 0.5
SCATTER NAME oprev1
ENDSCAN
In order to complete a mortality table I want to use the Yearslived and survivors data (which were produced using the SCANs above) to get life expectancy data as follows. Say we have the simplified table:
SURVIVORS YEARSLIVED LIFEEXP
100 0 ?
80 90 ?
60 70 ?
40 50 ?
20 30 ?
0 10 ?
Then each LIFEEXP record should be the sum of the remaining YEARSLIVED records divided by the corresponding Survivors record, i.e:
LIFEEXP (1) = (90+70+50+30+10)/100
LIFEEXP (2) = (70+50+30+10)/80
...and so on.
I attempted to do this with a similar SCAN approach - see below:
Go 1
SCATTER NAME Oprev2
SCAN rest
replace lifeexp WITH ((SUM yearslived Rest) - oprev2.yearslived) / oprev2.survivors
SCATTER NAME oprev2
ENDSCAN
But here I get the error message "Function name is missing)." Help tells me this is probably because the function contains too many arguments.
So I then also tried to break things down and first use SCAN just to get all of my SUM REST data, as follows:
SCAN rest
SUM yearslived REST
END SCAN
... in the hope that I could get this data, define it as a variable, and create a simpler SCAN function above. However, I seem to be doing something wrong here as well, as instead of getting all necessary sums (first the sum of rows 2 to end, then 3 to end, etc.), I only get one sum, of all the yearslived data. In other words, using the sample data, I am given just 250, instead of the list 250, 160, 90, 40, 10.
What am I doing wrong? And more generally, how can I create a loop in Foxpro that includes a function where you Sum up all remaining data in a specific column over and over again (first 2nd through last record, then 3rd through last record, and so on)?
Any help will be much appreciated!
TM
Well you are really hiding the important detail, your table's structure, sample data and desired output. Then it is mostly guess work which have a high chance of to be true.
You seem to be trying to do something like this:
Create Cursor Mortality (Survivors i, YearsLived i, LifeExp b)
Local ix, oprev1
For ix=100 To 0 Step -20
Insert Into Mortality (Survivors, YearsLived) Values (m.ix,0)
Endfor
Locate
Survivors = Mortality.Survivors
Skip
Scan Rest
Replace YearsLived With (m.Survivors + Mortality.Survivors) * 0.5
Survivors = Mortality.Survivors
Endscan
*** Here is the part that deals with your sum problem
Local nRecNo, nSum
Scan
* Save current recnord number
nRecNo = Recno()
Skip
* Sum REST after skipping to next row
Sum YearsLived Rest To nSum
* Position back to row where we started
Go m.nRecNo
* Do the replacement
Replace LifeExp With Iif(Survivors=0,0,m.nSum/Survivors)
* ENDSCAN would implicitly move to next record
Endscan
* We are done. Go first record and browse
Locate
Browse
While there are N ways to do this in VFP, this is one xbase approach to do that and relatively simple to understand IMHO.
Where did you go wrong?
Well, you tried to use SUM as if it were a function, but it is a command. There is SUM() function for SQL as an aggregate function but here you are using the xBase command SUM.
EDIT: And BTW in this code:
SCAN rest
SUM yearslived REST
ENDSCAN
What you are doing is, starting a SCAN with a scope of REST, in loop you are using another scoped command
SUM yearslived REST
This effectively does the summing on the REST of records and places the record pointer to bottom. Endscan further advances it to eof(). Thus it only works for the first record.

Calculating days in Ruby

I have an issue where, I'm trying to work out if a certain alert on a webpage is calculating sums correctly. I'm using Capybara and Cucumber.
I have an alert that calculates records that expire within 30 days. When selecting this alert, the records are listed in a table and the date is presented in the following format, "1 feb 2016"
What I want to do is somehow take today's date, compare it to the date returned in the table and ensure that it's >= 30 days from the date in the alert.
I'm able to set today's date as the same format using Time.strftime etc.
When I try things like:
And(/^I can see record "([\d]*)" MOT is calculated due within 30 days$/) do |selection1|
today = Time.now.strftime('%l %b %Y')
thirty_days = (today + 30)
first_30day_mot = first('#clickable-rows > tbody > tr:nth-child(' + selection1 + ') > td:nth-child(3)')
if today + first_30day_mot <= thirty_days
puts 'alert correct'
else
(error handler here)
end
end
As you can see, this is quite a mess.
I keep getting the error TypeError: no implicit conversion of Fixnum into String
If anyone can think of a neater way to do this, please put me out of my misery.
Thanks
There are at least a couple of things wrong with your attempt.
You're converting dates to strings and then trying to compare lengths of time with strings. You should be converting strings to dates and then comparing them
#first returns the element in the page not the contents of the element
It's not 100% clear from your code what you're trying to do, but from the test naming I think you just want to make sure the date in the 3rd td cell (which is in the 1 feb 2016 format) of a given row is less than 30 days from now. If so the following should do what you want
mot_element = first("#clickable-rows > tbody > tr:nth-child(#{selection1}) > td:nth-child(3)")
date_of_mot = Date.parse(mot_element.text)
if (date_of_mot - Date.today) < 30
puts 'alert correct'
else
#error handler
end
Beyond that, I'm not sure why you're using #first with that selector since it seems like it should only ever match one element on the page, so you might want to swap that to #find instead, which would get you the benefits of Capybaras waiting behavior. If you do actually need #first, you might consider passing the minimum: 1 option to make sure it waits a bit for the matching element to appear on the page (if this is the first step after clicking a button to go to a new page for instance)
Convert selection1 to the string explicitly (or, better, use string interpolation):
first_30day_mot = first("#clickable-rows > tbody > tr:nth-child(#{selection1}) > td:nth-child(3)")
Also, I suspect that one line below it should be converted to integer to add it to today:
first_30day_mot.to_i <= 30
UPD OK, I finally got time to take a more thorough look at. You do not need all these voodoo magic with days calculus:
# today = Time.now.strftime('%l %b %Y') # today will be a string " 3 Feb 2016"
# thirty_days = (today + 30) this was causing an error
# correct:
# today = DateTime.now # correct, but not needed
# plus_30_days = today + 30.days # correct, but not needed
first_30day_mot = first("#clickable-rows > tbody > tr:nth-child(#{selection1}) > td:nth-child(3)")
if 30 > first_30day_mot.to_i
...
Hope it helps.
I'd strongly recommend not using Cucumber to do this sort of test. You'll find its:
Quite hard to set up
Has a high runtime cost
Doesn't give enough benefit to justify the setup/runtime costs
Instead consider writing a unit test of the thing that provides the date. Generally a good unit test can easily run 10 to 100 times faster than a scenario.
Whilst with a single scenario you won't experience that much pain, once you have alot of scenarios like this the pain will accumulate. Part of the art of using Cucumber is to get plenty of bang for each scenario you write.

How can I select the second last item in a xpath query?

I'm new to xpath and I understand how to get a range of values in xpath:
/bookstore/book[position()>=2 and position()<=10]
but in my case, I need to get above 2 and one less then the total(so if there's 10 then I need 9, or if there's 5, I need up to the 4th spot). I'm applying my code to different pages and the number of entries is not always the same.
In python, I could do something like book[2:-2], but I'm unsure if I can do this within xpath.
You can use last() which represents the last item in the context:
/bookstore/book[position()>=2 and position() <= (last() - 1)]
In my case this was working for me to get last but one element
/bookstore/book[position() = (last() - 1)]

Performing multiple operations if condition is satisfied in ternary operator in linq

I am a beginner in LINQ.I want to perform some conditional operation lik follows,
(from emp in Employees
let DOB=emp.BirthDate.GetValueOrDefault()
let year=DOB.Year
let month=DOB.Month
let EmpAgeInYearsToday=DateTime.Now.Year-year
let EmpAgeInMonthToday=DateTime.Now.Month-month
let temp_year=(EmpAgeInYearsToday-1)
let ExactNoOfMonths_temp=EmpAgeInMonthToday<0?temp_year:EmpAgeInMonthToday
let ExactNoOfMonths=EmpAgeInMonthToday<0?EmpAgeInMonthToday+12&temp_year:EmpAgeInMonthToday
select new{emp.EmployeeID,DOB,
EmployeeAgeToday=EmpAgeInYearsToday+" Years "+ExactNoOfMonths+" Months ").Dump();
Here,
let ExactNoOfMonths=EmpAgeInMonthToday<0?EmpAgeInMonthToday+12&temp_year:EmpAgeInMonthToday
This part is not working. The expression in the left side of & alone is getting executed.I want to perform both the operations. How to achieve this?How to perform multiple operations when the condition is satisfied?
Is there any Other alternate way for doing this?
I think what you mean is something like this:
ExactNoOfMonths = EmpAgeInMonthToday < 0 ?
EmpAgeInMonthToday + 12 :
temp_year ?
EmpAgeInMonthToday :
somethingElse
but there should be a third value (somethingElse) for when EmpAgeInMonthToday >= 0 and temp_year = false.
Edit
What you want is actually pretty complicated. You better just fetch the dates of birth in memory and do the calculation in plain C#.
This CodeProject link gives a possible approach. As you'll see you can't avoid leap years and month lengths: the difference between Feb 28 and Mar 28 is 1 month in a normal year, 1 month and 1 day in a leap year.

Are there sequence-operator implementations in .NET 4.0?

With that I mean similar to the Linq join, group, distinct, etc. only working on sequences of values, not collections.
The difference between a sequence and a collection is that a sequence might be infinite in length, whereas a collection is finite.
Let me give you an example:
var c1 = new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var c2 = FunctionThatYieldsFibonacciNumbers();
var c3 = c1.Except(c2);
This does not work. The implementation of Except does not work on the basis that the numbers in either collection will be strictly ascending or descending, so it first tries to gather all the values from the second collection into a set (or similar), and only after that will it start enumerating the first collection.
Assuming that the function above is just a While-loop that doesn't terminate unless you explicitly stop enumerating it, the above code will fail with a out-of-memory exception.
But, given that I have collections that are considered to be strictly ascending, or descending, are there any implementations already in .NET 4.0 that can do:
Give me all values common to both (inner join)
Give me all values of both (union/outer join)
Give me all values in sequence #1 that isn't in sequence #2
I need this type of functionality related to a scheduling system I need to build, where I need to do things like:
c1 = the 1st and 15th of every month from january 2010 and onwards
c2 = weekdays from 2010 and onwards
c3 = all days in 2010-2012
c4 = c1 and c2 and c3
This would basically give me every 1st and 15th of every month in 2010 through 2012, but only when those dates fall on weekdays.
With such functions it would be much easier to generate the values in question without explicitly having to build collections out of them. In the above example, building the first two collections would need to know the constraint of the third collection, and the examples can become much more complex than the above.
I'd say that the LINQ operators already work on general sequences - but they're not designed to work specifically for monotonic sequences, which is what you've got here.
It wouldn't be too hard to write such things, I suspect - but I don't believe anything's built-in; there isn't even anything for this scenario in System.Interactive, as far as I can see.
You may onsider the Seq module of F#, which is automatically invoked by using special F# language constructs like 1 .. 10 which generates a sequence. It supports infinite sequences the way you describe, because it allows for lazy evaluation. Using F# may or may not be trivial in your situation. However, it shouldn't be too hard to use the Seq module directly from C# (but I haven't tried it myself).
Following this Mandelbrot example shows a way to use infinite sequences with C# by hiding yield. Not sure it brings you closer to what you want, but it might help.
EDIT
While you already commented that it isn't worthwhile in your current project and accepted an answer to your question, I was intrigued by the idea and conjured up a little example.
It appeared to be rather trivial and works well in C# with .NET 3.5 and .NET 4.0, by simple including FSharp.Core.dll (download it for .NET 3.5) to your references. Here's an out-of-the box example of an infinite sequence implementing your first use-case:
// place in your using-section:
using Microsoft.FSharp.Collections;
using Microsoft.FSharp.Core;
// [...]
// trivial 1st and 15th of the month filter, starting Jan 1, 2010.
Func<int, DateTime> firstAndFifteenth = (int i) =>
{
int year = i / 24 + 2010;
int day = i % 2 != 0 ? 15 : 1;
int month = ((int)i / 2) % 12 + 1;
return new DateTime(year, month, day);
};
// convert func to keep F# happy
var fsharpFunc = FSharpFunc<int, DateTime>.FromConverter(
new Converter<int, DateTime>(firstAndFifteenth));
// infinite sequence, returns IEnumerable
var infSeq = SeqModule.InitializeInfinite<DateTime>(fsharpFunc);
// first 100 dates
foreach (var dt in infSeq.Take(100))
Debug.WriteLine("Date is now: {0:MM-dd-yyy}", dt);
Output is as can be expected, first few lines like so:
Date is now: 01-01-2010
Date is now: 01-15-2010
Date is now: 02-01-2010
Date is now: 02-15-2010
Date is now: 03-01-2010

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