Need to check if the value in one cell is correct or not

[RobertoB]

Hi I have a complex validation process at hand and I wonder if there is any
way I can do this with Excel:

My data looks as follows

A1 B1 C1 D1
Code Decription Value Multiple Yes/No
6460880 Base1
6460885 Base2

I need to fill the values for columns C and D using a validation formula for
the number on Column A

The validation for numbers goes like this - starting from the back of the
number, all the digits of the number are added together. Every other number
is multiplied by two, and if that makes it a two digit number, each digit is
added onto the total separately (eg 8 * 2 = 16 = 1+6 = 7). The total must be
a multiple of 10. So, for example for the Code 6460880 we get the following;

6460880 =
6 4 6 0 8 8 0
*1 *2 *1 *2 *1 *2 *1
=
6+ 8+ 6+0 +8 +7+0
=35 (which is not a multiple of 10 and therefore the value for C is £5 and
for D is NO)

But for the next value
6460885
=
6 4 6 0 8 8 5
*1 *2 *1 *2 *1 *2 *1
=
6+ 8+ 6+0 +8 +7+5
=40 (So the value for C is 40 and the value for D is YES as it is a multiple
of 10) So the table will look as follows:

A1 B1 C1 D1
Code Decription Value Multiple of 10 Yes/No
6460880 Base1 35 NO
6460885 Base2 40 YES

I am using Offfice Excel 2003

Thank you for any advice you can provide

 

[Charabeuh]

hello,
I don'tknow where is the back of a number.
I supposed it is 6 in 6460880.

you could try this function:

Public Function Valid(Sinput As String)
Dim I, X, Xsum
For I = 1 To Len(Sinput)
X = (2 - (I Mod 2)) * Mid(Sinput, I, 1)
Xsum = Xsum + X \ 10 + (X Mod 10)
Next I
Valid = Xsum
End Function

into C2 put the formula : =valid(A2)
into D2 put the formula : =if( mod(C2,10) =)=0,"YES","NO")

if the back of the number is 0 than replace
For I = 1 To Len(Sinput)
with
For I = Len(Sinput) to 1 step -1

 

[Bernard Liengme]

If the number in A2 is always 7 digits then this will give the sum-of-digits
times {1,2,1,2,1,2,1}
=SUMPRODUCT(--(MID(A2,ROW(Sheet1!$A$1:$A$7),1)),{1;2;1;2;1;2;1})
But that ignores the complication of "each digit is added onto the total
separately (eg 8 * 2 = 16 = 1+6 = 7)"

If this answer is in C2, we can test for multiple of 10 with
=IF(MOD(C2,10),"No","Yes")

I might find time on Monday to write a UDF to include the complications
mentioned above. Please revisit the newsgroup or email me direct (get my
email from my website)

If you are unfamiliar with UDF, you may wish to read one or more of these
David McRitchie's site on "getting started" with VBA
http://www.mvps.org/dmcritchie/excel/getstarted.htm

Debra Dalgleish's "Adding Code to a Workbook"
http://www.contextures.com:80/xlvba01.html

Ron de Bruin's intro to macros:
http://www.rondebruin.nl/code.htm

Jon Peltier's site:
http://peltiertech.com/WordPress/2008/03/09/how-to-use-someone-else's-macro/

(General, Regular and Standard modules all describe the same thing.)

best wishes

 

[Charabeuh]

sorry !
if the back of the number is 0 than the function should be;
you could try this function:

Public Function Valid(Sinput As String)
Dim I, X, Xsum
For I = 1 To Len(Sinput)
X = (2 - (I Mod 2)) * Mid(Sinput, Len(Sinput)-I+1, 1)
Xsum = Xsum + X \ 10 + (X Mod 10)
Next I
Valid = Xsum
End Function

 

[Rick Rothstein]

If the number in A2 is always 7 digits then this will give the

sum-of-digits times {1,2,1,2,1,2,1}
=SUMPRODUCT(--(MID(A2,ROW(Sheet1!$A$1:$A$7),1)),{1;2;1;2;1;2;1})
But that ignores the complication of "each digit is added onto the total
separately (eg 8 * 2 = 16 = 1+6 = 7)"

This modification to your formula handles the "complication" as you call it
(again, for 7-digit numbers only)...

=SUMPRODUCT(MOD(MID(A1,ROW($A$1:$A$7),1)*{1;2;1;2;1;2;1},9))

Summing the digits of a number repeatedly in order to produce a single digit
is called (in mathematical circles) "casting out nines" and it is equivalent
to finding the modulus (what the MOD function returns) of the number with
respect to 9. That is...

SumOfDigits: =MOD(Number,9)

So I changed your comma version of the SUMPRODUCT function to the
multiplication version and then just applied the above MOD function call to
the original value being presented to the SUMPRODUCT function.

 

[Rick Rothstein]

SumOfDigits: =MOD(Number,9)

Just so someone doesn't misinterpret the above statement when reviewing the
archives in the future, the above would more appropriately be described this
way...

RepeatedlySummingDigits: =MOD(Number,9)

 

[Rick Rothstein]

My modification to your formula does NOT work correctly if there is a 9 in
the value in an odd numbered position (counting from the back of the number)
because casting out the nines for it reduces it value to 0 whereas it should
remain a 9 because it is a single digit number that is *not* multiplied by
2. My SumOfDigits (or as I called it in my follow up posting,
RepeatedlySummingDigits) statement is correct; however, it is being applied
to all the digits as opposed to only those digits that get multiplied by 2.
End result... do NOT use my modification.

 

[Bernard Liengme]

Rick,
I am impressed! When I read your explanation (casting out nines) my old
memory had a flash but I would never have got your formula without weeks of
work. Thanks
Bernard

 

[Rick Rothstein]

Don't be so impressed... unfortunately, there is a problem with the formula.
The "casting out nines" part is correct, but it gets applied to too many of
the digits. If you have a 9 in a position that does not get multiplied by 2,
it should remain a 9 for the addition... unfortunately, my modification to
your formula makes it a 0 (that is what the MOD 9 does) because there is no
filter within it as to whether the digit gets multiplied by 2 or not.

 

[Rick Rothstein]

This formula seems to work correctly (again, for 7-digit numbers only)...

=SUMPRODUCT(9*(MID(A2,ROW($A$1:$A$7),1)="9")+MOD((MID(A2,ROW($A$1:$A$7),1))*{1;2;1;2;1;2;1},9))

As a side note.. the relationship I gave earlier, namely...

RepeatedlySummingDigits: =MOD(Number,9)

is not entirely accurate as it will take a number whose digits total 9 and
reduce it to 0 whereas "casting out nines" would stop the reduction at the
single digit 9 and **not** reduce it further (to a value of 0). The actual
mathematical relationship for "casting out nines" would appear to be this...

RepeatedlySummingDigits: =9*(Number<>0)*(MOD(Number,9)=0)+MOD(Number,9)

 

[Rick Rothstein]

This formula seems to work correctly (again, for 7-digit numbers only),
handling the "complication" that you mentioned correctly...

=SUMPRODUCT(9*(MID(A2,ROW($A$1:$A$7),1)="9")+MOD((MID(A2,ROW($A$1:$A$7),1))*{1;2;1;2;1;2;1},9))

As a side note.. the relationship I gave earlier, namely...

RepeatedlySummingDigits: =MOD(Number,9)

is not entirely accurate as it will take a number whose digits total 9 and
reduce it to 0 whereas "casting out nines" would stop the reduction at the
single digit 9 and **not** reduce it further (to a value of 0). The actual
mathematical relationship for "casting out nines" would appear to be this...

RepeatedlySummingDigits: =9*(Number<>0)*(MOD(Number,9)=0)+MOD(Number,9)

 

[Rick Rothstein]

Here is a modification to your formula (including modifications from the
other discussions I posted) which will handle *any* size "number" that you
can enter into an Excel cell (if the number is entered as text, then the
limit is very large, but I didn't test to see how big the text number could
be and still work) and which properly handles what you called "the
complication"...

=SUMPRODUCT(9*(MID(A1,ROW(INDIRECT("$A$1:$A$"&LEN(A1))),1)="9")+MOD((MID(A1,ROW(INDIRECT("$A$1:$A$"&LEN(A1))),1))*(1+(MOD(LEN(A1)-ROW(INDIRECT("A$1:A$"&LEN(A1))),2)=1)),9))

 

[Bernard Liengme]

I came up with this while showering
=SUMPRODUCT(MOD(MID(A1,ROW($A$1:$A$7),1)*{1;2;1;2;1;2;1},9))+SUMPRODUCT(--(MID(A1,ROW($A$1:$A$7),1)*{1;0;1;0;1;0;1}=9))*9

Yours is shorter,
Have a good night
Bernard