SORT-strange behaviour on sorting double dimensioned array.

[billknott]

Is there some limitation of the SORT command?
I have a double dimensioned array with 8 second elements any one of which needs variously to be sorted during program operation.
The array first element value (rows) may at times be shorter than the number of second elements (columns).
If a sort is done using a sort key value greater than the number of rows, then it crashes.
If the sort key used is less than the number of rows, then it works
If the number of rows is greater than the number of columns then it works using any valid sort key.
The error message when it crashes says "out of range for array$("
This appears to defy logic as the key used for the sort is related to the second array column element but
the error handler appears to be focused on the first array row element.
Am I missing something here? I have played around with this for a while but I can't see what is wrong!
To illustrate I have simplified the code down to the essentials to demonstrate what is happening.

LastRecordNumber = 5   'change to experiment with LastRecordNumber lower than second array element
dim List$(LastRecordNumber,8)

gosub [ArrayData]

for x = 0 to LastRecordNumber
for y = 0 to 8
print List$(x,y  ) 'all good for all array element values
next
next
print:print

z = 2     'value for second element of array. This works fine for all z values up to LastRecordNumber

for n = 1 to LastRecordNumber
print "this is List$(";n;",";z;") - " + List$(n,z)    'works for all z values up to 8
next

print:print "start first sort"
sort List$(),LastRecordNumber, 1, z   'works for all z values up to LastRecordNumber , crashes with any z value above LastRecordNumber lower than second array element
for n = 1 to LastRecordNumber
print List$(n,z)
next

print:print "start second sort"
sort List$(), 1, LastRecordNumber,z   'works for all z values up to LastRecordNumber , crashes with any z value above LastRecordNumber lower than second array element
for n = 1 to LastRecordNumber
print List$(n,z)
next
print:print

wait

[ArrayData]

List$(0,0)="Supplier":List$(0,1)="Finish Type":List$(0,2)="Finish Colour":List$(0,3)="Mx":List$(0,4)="Board"
List$(0,5)="Match":List$(0,6)="Panelcode":List$(0,7)="Available":List$(0,8)="0"

List$(1,0)="PDM Distributors Ltd":List$(1,1)="Foil":List$(1,2)="Buttermilk":List$(1,3)="1.5"
List$(1,4)="U108 ST9":List$(1,5)="Exact":List$(1,6)="2":List$(1,7)="Yes":List$(1,8)="1"

List$(2,0)="Mason Distribution Ltd":List$(2,1)="Urbani":List$(2,2)="Light Grey":List$(2,3)="1.5"
List$(2,4)="U732":List$(2,5)="Close":List$(2,6)="1":List$(2,7)="Yes":List$(2,8)="2"

List$(3,0)="Panel Products Ltd":List$(3,1)="Vinyl":List$(3,2)="Grey Onyx Matt":List$(3,3)="1.2"
List$(3,4)="U960 ST9":List$(3,5)="Exact":List$(3,6)="1":List$(3,7)="Yes":List$(3,8)="3"

List$(4,0)="Bridgeton & Son Ltd":List$(4,1)="Laquer":List$(4,2)="red alder":List$(4,3)="1.6"
List$(4,4)="U700 ST8":List$(4,5)="Good":List$(4,6)="4":List$(4,7)="reset":List$(4,8)="4"

List$(5,0)="A. Brown & Sons":List$(5,1)="Vinyl":List$(5,2)="Grained Ivory":List$(5,3)="1"
List$(5,4)="U104 ST27":List$(5,5)="Exact":List$(5,6)="3":List$(5,7)="Yes":List$(5,8)="5"

return

[Rod]

Yeah, it is a known bug. Gold star though for presentation and clarity describing the problem :)

Sort
Sort a(),r,c,col if r is less than c sorting breaks when col is >r
Bug

Bugs and gochas alycesrestaurant.com/lbpe/Bugs%20and%20Gotchas.html

[billknott]

Gosh! that was quick Rod.
At least now I can stop going round in ever decreasing circles wondering what I have done wrong.
The array is going to be converted to a single dimensioned array for displaying in a listbox, so
I guess I will make the minimum number of rows no less than the number of second elements and include
empty strings in the unused rows, so that these will not show up in the display.
Thanks for the quick response.

[Rod]

Good plan, you make it an easy workaround.

[billknott]

OK, so here it is again. This time with a workaround and the conversion for a listbox.


LastRecordNumber = 5      'change to experiment with LastRecordNumber lower than second array element
dim List$(LastRecordNumber,8)
dim copyList$(LastRecordNumber,8)

gosub [ArrayData]

for x = 0 to LastRecordNumber
   for y = 0 to 8
       print List$(x,y)        'all good for all array element values
   next
next
print:print

z = 4   'value for second element of array. This works fine for all z values up to LastRecordNumber

for n = 1 to LastRecordNumber
   print "this is List$(";n;",";z;") - " + List$(n,z)      'works for all z values up to 8
next

print:print "start first sort"
sort List$(),LastRecordNumber, 1, z     'works for all z values up to LastRecordNumber , crashes with any z value above LastRecordNumber but lower than second array element
for n = 1 to LastRecordNumber
   print List$(n,z)
next

print:print "start second sort"
sort List$(), 1, LastRecordNumber,z     'works for all z values up to LastRecordNumber , crashes with any z value above LastRecordNumber but lower than second array element
for n = 1 to LastRecordNumber
   print List$(n,z)
next
print:print
gosub [ConvertForListbox]
wait

[ArrayData]
List$(0,0)="Supplier":List$(0,1)="Finish Type":List$(0,2)="Finish Colour":List$(0,3)="Mx":List$(0,4)="Board"
List$(0,5)="Match":List$(0,6)="Panelcode":List$(0,7)="Available":List$(0,8)="0"

List$(1,0)="PDM Distributors Ltd":List$(1,1)="Foil":List$(1,2)="Buttermilk":List$(1,3)="1.5"
List$(1,4)="U108 ST9":List$(1,5)="Exact":List$(1,6)="2":List$(1,7)="Yes":List$(1,8)="1"

List$(2,0)="Mason Distribution Ltd":List$(2,1)="Urbani":List$(2,2)="Light Grey":List$(2,3)="1.5"
List$(2,4)="U732":List$(2,5)="Close":List$(2,6)="1":List$(2,7)="Yes":List$(2,8)="2"

List$(3,0)="Panel Products Ltd":List$(3,1)="Vinyl":List$(3,2)="Grey Onyx Matt":List$(3,3)="1.2"
List$(3,4)="U960 ST9":List$(3,5)="Exact":List$(3,6)="1":List$(3,7)="Yes":List$(3,8)="3"

List$(4,0)="Bridgeton & Son Ltd":List$(4,1)="Laquer":List$(4,2)="red alder":List$(4,3)="1.6"
List$(4,4)="U700 ST8":List$(4,5)="Good":List$(4,6)="4":List$(4,7)="reset":List$(4,8)="4"

List$(5,0)="A. Brown & Sons":List$(5,1)="Vinyl":List$(5,2)="Grained Ivory":List$(5,3)="1"
List$(5,4)="U104 ST27":List$(5,5)="Exact":List$(5,6)="3":List$(5,7)="Yes":List$(5,8)="5"


'change to handle a LastRecordNumber lower than second array element due to known bug in SORT command
if LastRecordNumber < 8 then
       redim copyList$(8,8)
   PRINT "fill copyList - First 0 to ";LastRecordNumber;" items"
       for x = 0 to LastRecordNumber
           for y = 0 to 8
               copyList$(x,y) = List$(x,y)
   print copyList$(x,y)
           next        
       next
   
       n = 8 - LastRecordNumber
   PRINT "fill copyList - Next ";n;" items"
       n=n-1 'need to start from next item along
       for x = 8-n to 8
           for y = 0 to 8
               copyList$(x,y) = str$(x)    'Shown to demonstrate only. You should replace this with an empty string so that when included
   print copyList$(x,y)                    'in the conversion to a single element array, it can be excluded from the listbox display
           next        
       next
       
       LastRecordNumber = 8
   PRINT "fill List - All 0 to ";LastRecordNumber;" items"
       redim List$(8,8)
           for x = 0 to LastRecordNumber
               for y = 0 to 8
                   List$(x,y) = copyList$(x,y)
   print List$(x,y)
               next        
           next
   end if
return

[ConvertForListbox]
'convert 2D array to 1D array ready for listbox
dim SingleList$(LastRecordNumber)
   for n=1 to LastRecordNumber  
       for y = 0 to 8          'truncate the string lengths to fit the available spaces for each item when sent to the listbox
           select case y
               case 0
                   if len(List$(n,y)) > 24 then
                       List$(n,y) = left$(List$(n,y), 24)
                   end if
               case 1
                   if len(List$(n,y)) > 17 then
                       List$(n,y) = left$(List$(n,y), 17)
                   end if
               case 2
                   if len(List$(n,y)) > 23 then
                       List$(n,y) = left$(List$(n,y), 23)
                   end if
               case 3
                   if len(List$(n,y)) > 6 then
                       List$(n,y) = left$(List$(n,y), 6)
                   end if
               case 4
                   if len(List$(n,y)) > 12 then
                       List$(n,y) = left$(List$(n,y), 12)
                   end if
               case 5
                   if len(List$(n,y)) > 10 then
                       List$(n,y) = left$(List$(n,y), 10)
                   end if
               case 6
                   if len(List$(n,y)) > 6 then
                       List$(n,y) = left$(List$(n,y), 6)
                   end if
               case 7
                   if len(List$(n,y)) > 5 then
                       List$(n,y) = left$(List$(n,y), 5)
                   end if
                   if List$(n,y) = "set" then    'convert set/reset to yes or no
                       List$(n,y) = "Yes"
                   end if
                   if List$(n,y) = "reset" then
                       List$(n,y) = "No "  'include the space to make same length string as yes
                   end if
               case 8
                    if len(List$(n,y)) > 12 then
                       List$(n,y) = left$(List$(n,y), 12)
                   end if
           end select                
       next            
       SingleList$(n) =  List$(n,0)+space$(24-(len(List$(n,0))))+" "+List$(n,1)+space$(17-(len(List$(n,1))))+" "+List$(n,2)+space$(23-(len(List$(n,2))))_ 'fill the Items array ready for the display
                       +" "+List$(n,3)+space$(6-(len(List$(n,3))))+" "+List$(n,4)+space$(12-(len(List$(n,4))))+" "+List$(n,5)+space$(10-(len(List$(n,5))))_
                       +space$(6-(len(List$(n,6)))/2)+List$(n,6)+space$(6-(len(List$(n,6)))/2)+"    "+List$(n,7)+using("############", val(List$(n,8)))  'this last item is the array records index number
       if val(List$(n,8)) = 0 then
           SingleList$(n) = ""         'this prevents any 'ghost' array items, introduced by the [EliminateSortCommandBug] procedure, that contain empty strings from showing up in the listbox display
       end if        
   next
   LastRecordNumber = n-1
   for n = 1 to LastRecordNumber
       print SingleList$(n)
   next    
   return