Problem to sort numbers

[papiosaur]

Hello,

i use sort option for this column but the sort is not good.

I have used ToNumber() and Val() command to convert strings to number.

Any ideas please?

Thanks for your help!

[plouf]

its obvius that they are sorted by as string, see the first 3 characters that this sort is ok, afaik they are always strings
imho you should , extract data, sort them manualy and throu back in order.

you have discuss this a few times in past, but you dont provide some working example so we can understand what you practically do
if, for example, you extract data out of a database (SQLite ?), you can ask database to export them in order for you

[airsoftsoftwair]

You could also specify a custom sort callback using Listview.CompareItems to solve the problem.

[plouf]

does this change listview logic from "text" to "number" ? and if yes what else can understand ? date ? currency?

[papiosaur]

@plouf: it's a JSON import, the sort is an option for many columns (date, name and numbers) in this project.

Personnaly, i understand why the sort don't work correctly, i just want a sort increase or decrease by number.

The sort should be the same for all type of datas:

A->Z then second letter, etc.
01-01-1900 -> 01-01-2024
0.0001 -> 999.9999

No?

I understand why i must do a custom sort callback using Listview.CompareItems to do a simple sort by number.

@Andreas: do you have an example of custom sort callback please?

Could you correct this problem for next RAPAGui please?

[airsoftsoftwair]

does this change listview logic from "text" to "number" ? and if yes what else can understand ? date ? currency?

It can understand everything you need. Your callback simply tells the listview how to sort the entries. This allows you to impose any sort logic you want on the listview. Numbers, dates, currencies, whatever.

Could you correct this problem for next RAPAGui please?

It's not a RapaGUI bug. As plouf has correctly said, by default all entries are sorted alphabetically and in that case it's correct to put 236550 after 1886087 because 2 comes after 1 in the alphabet. If you want numerical sorting, you need to use a custom callback using Listview.CompareItems to do that. Here's what your example looks like with a custom callback:

Code: Select all

@REQUIRE "RapaGUI"

Function p_CmpFunc(e1, e2)

	Local v1, v2 = Val(e1), Val(e2)
	
	If v1 < v2 Then Return(-1)
	If v1 > v2 Then Return(1)
		
	Return(0)
		
EndFunction
	
moai.CreateApp([[
<?xml version="1.0" encoding="iso-8859-1"?>
<application>
   <window title="Test program">
      <vgroup>
	 <listview id="lv" notify="compareitems" forcemode="dataview">
	 	<column sortable="true"/>
	 </listview>
      </vgroup>
   </window>
</application>
]])

t = {1289255, 1393876, 1611837, 172877653, 1872262, 1886087, 236550,
	2690523, 355653720, 36295634, 4617075, 4848326, 5497692, 
	61047095, 6256502}	

InstallEventHandler({RapaGUI = Function(msg)
	
	If msg.attribute = "CompareItems" Then Return(p_CmpFunc(msg.entry1, msg.entry2))

EndFunction})
		
For Local k = 0 To ListItems(t) - 1 Do moai.DoMethod("lv", "insert", 0, t[k])

Repeat
	WaitEvent
Forever 

[papiosaur]

Thanks a lot Andreas for your example!

Maybe should be nice to add an option in listview declaration like type="numeric", "date", "alphabetic" to have a specific sort without a custum sort.

I have watched your example but how i must do if i have 1500 entries? My problem here, i add new entries regulary...

[papiosaur]

soory, i would like to say "column" declaration and not listview...

[plouf]

does this change listview logic from "text" to "number" ? and if yes what else can understand ? date ? currency?

It can understand everything you need. Your callback simply tells the listview how to sort the entries. This allows you to impose any sort logic you want on the listview. Numbers, dates, currencies, whatever.

i can not understand how can this so "smart"
i try with your example the following

Code: Select all

t = {"21/12/2020","4/5/2021","30/01/1651","12/12/1900"}

no matter if p_CmpFunc return -1 0 or 1 , date is not correct. do i miss something or is just numbers<>characters

[jPV]

does this change listview logic from "text" to "number" ? and if yes what else can understand ? date ? currency?

It can understand everything you need. Your callback simply tells the listview how to sort the entries. This allows you to impose any sort logic you want on the listview. Numbers, dates, currencies, whatever.

i can not understand how can this so "smart"
i try with your example the following

Code: Select all

t = {"21/12/2020","4/5/2021","30/01/1651","12/12/1900"}

no matter if p_CmpFunc return -1 0 or 1 , date is not correct. do i miss something or is just numbers<>characters

The p_CmpFunc just gets two values and returns -1, 0, or 1 after it has decided in which order these two values should be. It's up to your own code how the order should be defined.

The previous example was only to convert numerical strings to numbers and compare them. Now when you have string data that has slashes in it, Val("21/12/2020") just gives 21 as the result. So you're comparing the data by the day numbers, not with the whole date.

Here's an example logic to compare dates in the format you gave (haven't thought if it's optimal by speed, but an example anyway):

Code: Select all

Function p_CmpFuncDate(e1, e2)

	Local d1$, m1$, y1$ = PatternFindStrShort(e1, "(%d+)/(%d+)/(%d+)")
	Local d2$, m2$, y2$ = PatternFindStrShort(e2, "(%d+)/(%d+)/(%d+)")
	Local v1, v2 = Val(FormatStr("%s%02s%02s", y1$, m1$, d1$)), Val(FormatStr("%s%02s%02s", y2$, m2$, d2$))

	If v1 < v2 Then Return(-1)
	If v1 > v2 Then Return(1)

	Return(0)

EndFunction

It picks day, month, and year from the input data, and converts them to numeric YearMonthDay format with padding zeroes in day and month. In this form it's easy to compare them again as numbers.

As told, you can write any kind sorting algorithms in this way, everything is possible But of course you have to modify the sorting algorithm to match your data.

I myself have written custom sorting algorithms in RNOArchive and RNOTunes, and probably somewhere else too. I have usually used Hollywood's own date format for dates, and then the compare function can just use CompareDates() function to determine the order. I also have made some generic sorting functions that operate in different ways according the column that has been clicked and have reversed sorting if clicking the same column again.