topic Re: Class function in QlikView

Class function

Thu, 14 Jun 2012 09:36:05 GMT

Hello community!

I just stared to use QlikView for my final thesis and even after reading several times some of the already existing posts and the Reference Manual, I am still facing some problems with the class function.

I am representing number of flights depending on the time of the day:

y-axes: number of flights (defined with the count function: count (Departures))
x-axes: time of the day (from 0:00 to 24:00)

I would like to represent the flights every 30 minutes; for instance, a flight corresponding to 10:25, represented together with the flights from 10:30, a flight from 12:45, with the flights from 13:00.

I think that this could be done with a class function, but I don't really know how. I was trying with: class(count(Departures),00:30), but definitely it is not the way to do it.

Thank you in advance for your help

Re: Class function

Thu, 14 Jun 2012 09:52:51 GMT

Only to clarify, what I would like to have is a frequency graph.

Re: Class function

lironbaram — Thu, 14 Jun 2012 11:15:35 GMT

hi check the attach example

Re: Class function

Thu, 14 Jun 2012 12:13:04 GMT

Thank you a lot for your answer, but I am working with a personal edition, which doesn't allow me to open other users' qvw files.

Re: Class function

lironbaram — Thu, 14 Jun 2012 12:19:57 GMT

hi attach is file with deom data

load it to a qlikview file

then create new bar chart

in the dimension add calulated dimension with this formula

time(left(class(aggr(DepartureTime,flightnumber),0.5/24),Index(class(aggr(DepartureTime,flightnumber),0.5/24),'<')-1),'hh:mm')

then add an expression with this formula

count

(flightnumber)

hope it helps you

Re: Class function

Thu, 14 Jun 2012 13:21:11 GMT

Thanks Liron, your aswer helped me to understand better this function and how to deal with the time. The result that your solution gives is exactly what I am looking for, but now the issue is that I only have one field: the Departures_Time, so instead of counting flight numbers, I am counting departure times (more precisely how many times a departure time appears in my data set).

I am trying to use your formula like following:

Calculated dimension:

=
time(left(class(aggr(Departure_Time),0.5/24),Index(class(aggr(Departure_Time),0.5/24),'<')-1),'hh:mm')

Expression: count (Departure_Time)

But no data is displayed in the graph.

I really thank you for any new suggestion you could give me.

Re: Class function

lironbaram — Thu, 14 Jun 2012 18:32:55 GMT

in order to get the number right

i suggest that in the load you will add index filed

add to the load script new field

when your load script should look like

load

Departure_Time,

rowno() as filghtnumber

from yourfile

then you can use the formula i sent or change your expression to

time(left(class(aggr(Departure_Time,Departure_Time),0.5/24),Index(class(aggr(Departure_Time,Departure_Time),0.5/24),'<')-1),'hh:mm')