How if nested works?

[#1]

Hi!

I am using if nested, but I am having performance problems. I would like to know how does qlikview evaluate the conditions. I mean, if the first condition is true then the other "if" conditions are not evaluated? or do all "if" conditions are evaluated always?

For example:

if(a=b,1,if(a=c,if(a=d,1,0)))

desired behaviour:

If a=b -> True, then qlikview returns 1 and ignores the other "if" statements. Is this the real behaviour?

Please help me to understand!

Thank you.

Linda

[PrashantSangle]

Hi,

Another possible solution is if possible move all complex expression in script.

Create flag according to that and use flag in expression.

Regards,

[jonathandienst]

I agree that some refactoring of your model and/or performing the calculations in the back end are the best solution. But in the meantime, you could try restating the expression:

     =If(RangeMax(a, b, c, d, ...., n) > 0, 1, 0)

Just fill in the RangeMax with all the values that you want to test for > 0. It may perform better than the if expression.

[#4]

Hi Marcus,

a, b, c.. are expressions like this:

if(isnull($(vLI($1,'P027','E050'))) and isnull($(vLS($1,'P027','E050'))),0,

if(isnull($(vLI($1,'P027','E050'))),if($(vValor($1,'P027','E050')) <= $(vLS($1,'P027','E050')),0,1),

if(isnull($(vLS($1,'P027','E050'))),if($(vValor($1,'P027','E050')) >= $(vLI($1,'P027','E050')),0,1),

if($(vValor($1,'P027','E050')) >= $(vLI($1,'P027','E050')) and $(vValor($1,'P027','E050')) <= $(vLS($1,'P027','E050')),0,1))))

$vLI, $vLS and $vValor are variables that return me values from the data using set analysis and taking into account the parameters that I send to them.

$vLI -> returns me the limit inferior of the year that the user has selected in the filter.

$vLS -> returns me the limit superior of the year that the user has selected in the filter.

$vValor -> returns me the value that I want to compare with limits.

Functionality: I compare if a value is out from limits superior and inferior. If it is out, returns "1", if not returns "0". 

The problem is that I need to compare 500 values. If at least one of them is out from limits my object (indicator) has to be painted red.

$variable code:

if(

a>0 or

b>0 or

c>0 or

...(500 comparisons more)

z>0 ,1,0)

indicator expression:

if($variable>0,1,0)

And it has to be dynamic, I mean, if the user select a date filter, the calculations have to be done at the moment, that's why I don't think I can put it within the script.

Another alternative that I have tested is to distribute the calculations in more than one indicator, it is faster but the problem is that too many objects on the sheet is still a performance problem.

That is the complete scenario. Hope you have any idea to improve the performance. Thank you!

[#5]

Thank you Jonathan, I will test it.

[#6]

Hi Max,

Thank you, as I explain to Marcus above, I don't think I can put the code within the script because it has to be dynamic, depending on a date filter that the user selects on the gui.

[#7]

Hi Jonathan,

I have tested with RangeMax but it takes the same time to be calculated

[marcus_sommer]

I have the feeling that your approach is somehow overcomplicated and that it could be simplified in any way. Please provide a small example:

Preparing examples for Upload - Reduction and Data Scrambling

Uploading a Sample

- Marcus