8 Replies Latest reply on Nov 3, 2015 1:34 PM by Peter Harris

Total Number of Boolean Transitions

Peter Harris Nov 2, 2015 3:23 PM

I have a data set with a field that has a Boolean value of T/F and would like to count the number of transitions between the two states. For eg. T T F T T would have 2 transitions while T T F F F would only have one.

Any pointers to the correct function would be appreciated.

Thanks for looking

Pete

1. Re: Total Number of Boolean Transitions

Alexander Mou Nov 2, 2015 5:03 PM (in response to Peter Harris)

Peter, attach a sample workbook or dataset if you want an exact and quick answer.
Here is my idea of counting them.

1.Convert t/f into numbers

if 'T' then 1
else 0
end

2.Use the Quick Table calculations to calculate the difference from previous vlaue.

3.Sum up the absolute values: Sum(ABS(Difference))
This gives you the number of transitions.
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2. Re: Total Number of Boolean Transitions

Peter Harris Nov 3, 2015 7:23 AM (in response to Alexander Mou)
Thanks Alexander this is helpful

I have attached a workbook with some simplified data. The field Panel.Growth is the parameter that i am looking at. I would like to calculate the number of times that this field changes from T to F for each antibiotic with a simple calculated field so that i can use the calculated value in some other calculations later. Any ideas would be appreciated.

Thanks

Test Data.twbx 70.2 KB
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3. Re: Total Number of Boolean Transitions

Alexander Mou Nov 3, 2015 12:14 PM (in response to Peter Harris)

Here is the result. Let me know if you have questions

https://public.tableau.com/views/ChangeCount/Dashboard1?:embed=y&:display_count=yes&:showTabs=y
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4. Re: Total Number of Boolean Transitions

Peter Harris Nov 3, 2015 12:52 PM (in response to Alexander Mou)

Thanks again Alexander this was very helpful

Pete
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5. Re: Total Number of Boolean Transitions

Alexander Mou Nov 3, 2015 1:11 PM (in response to Peter Harris)

Sounds like this is not exactly what u expected .

On Tuesday, November 3, 2015, Peter Harris <
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6. Re: Total Number of Boolean Transitions

Peter Harris Nov 3, 2015 1:28 PM (in response to Alexander Mou)

Alex

Firstly, I appreciate the work that you have put in to this and your method definitely yields the correct number for total transitions between the two states. This is further than I was able to get and your code is more elegant than my solution. The problem that I am facing is that I need to use the calculated number as a variable in further calculations and this does not seem possible with the results of table calculations. The count of T/F transitions was an idea as to how we might achieve a more complicated filter, I may have to come up with another method.
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7. Re: Total Number of Boolean Transitions

Alexander Mou Nov 3, 2015 1:32 PM (in response to Peter Harris)

You got what you asked for.

Anything is possible with tableau.

On Tuesday, November 3, 2015, Peter Harris <
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8. Re: Total Number of Boolean Transitions

Peter Harris Nov 3, 2015 1:34 PM (in response to Alexander Mou)

You are correct…sometimes as a newbie to scripting in Tableau part of the issue is learning what question to ask

Thanks for your help
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