BUG: 1D Array Sort is not sorting Array of Classes and Array of Clusters contain Classes

[JCC_(SK)]

function 'Sort 1D array'

 I wanted sort Array of Clusters [number and Class]. But to my surprise LV is not like it.

OK, I don't need sort Array of Classes. But maybe one time in future I will. 🙂

When 'Search 1D array' is working with classes I don't understand why 'Sort 1D array' is not working.

 This problem is in LabVIEW 8.2, 8.5 and 2009

[Ben · Accepted solution]

I would think that the Search 1d array function can deal with each element in the array as an agregate while to sort requires accessing the private data within the class data and carrying this even farther...

Say all of the elements are of class Parent and one tow children which both have private data that are uniqie from each and not present in the parents class...

How do handle tie-breakers when there are different fileds to sort on?

Ben

[JCC_(SK)]

My goal is have cluster [number and class]. Number is fitness of Class.

I don't need sort Array of Classes.

You are right there could be problem with private data in class and with children's new data.

Why Search 1D Array is working [I didn't test it]?

P.S.: I could hide Class in Variant in cluster and after everything will be fine 😉

Message Edited by JCC (SK) on 04-13-2010 05:19 PM

Message Edited by JCC (SK) on 04-13-2010 05:22 PM

[tst]

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JCC (SK) wrote:

Why Search 1D Array is working [I didn't test it]?

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Because searching an array is defined - is this element in the array or not?

Sorting is not defined, because different classes are different data types and each data type needs its own definition for sorting (e.g. for strings, you need to decide whether b>C, etc.). You can implement your own sort VI for your class hierarchy, which will accept an array of these classes and use whatever logic you want to sort the array.

[JCC_(SK)]

Guys! You are not helping me!

🙂

[Ben]

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JCC (SK) wrote:

Guys! You are not helping me!

🙂

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So this is not an achedemic Q?

In that case I'll throw out an idea to get the conversation started.

In the parent class create a method that returns the ranking for that object instance. Sort the rankings and then apply that sort back to the original array.

Ben 

[JCC_(SK)]

I could program everything but I hoped that something will LV/NI do 😉

[tst]

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JCC (SK) wrote:
I could program everything but I hoped that something will LV/NI do 😉

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How can NI do anything? Sorting an array of objects is completely meaningless without an algorithm, which you have to provide. I'm not sure what the problem is, since building such a VI should be very simple once you decide how you want to sort the data.

[Darren]

I don't see any compelling reason why we should break that wire.  Putting arbitrary data in an array of clusters along with something to sort by is a really common use case.  I've filed CAR# 219940 on this issue.  Incidentally, the broken wire has been the behavior since LV Classes were introduced in LabVIEW 8.2.

Message Edited by Darren on 04-13-2010 04:12 PM

[Ben]

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Darren wrote:

I don't see any compelling reason why we should break that wire.  Putting arbitrary data in an array of clusters along with something to sort by is a really common use case.  I've filed CAR# 219940 on this issue.  Incidentally, the broken wire has been the behavior since LV Classes were introduced in LabVIEW 8.2.

Message Edited by Darren on 04-13-2010 04:12 PM

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To sort you have to get at the stuff in the private data and you aren't allowed to look a that outside the class. Beraking the wire enforces that. Seems right to me.

Even if we say operators are allowed, an empty parent class with two different children one with a numeric and another with just a string, how to define a sort of tht type?

So how is this a bug?

Ben