division operation

[Bonowox]

Hello everyone!
Why is my query not showing the correct result when dividing two numbers?
For example:
if I divide -24.40 by 24.40 I get the result -0.983870967741935
or if I divide -24.80 by -24.80 I get the result -0.873239436619718
But it's not like that every time. In the query table, I have several divisions with these numbers, and sometimes it shows me the correct result, sometimes not

 

[cheekybuddha]

You have defined the datatype for your field as Double or Single floating point.

These datatypes will have rounding errors.

Use Decimal datatype instead or, even better, Currency if you are not interested in more than 4 decimal places

 

[Bonowox]

You have defined the datatype for your field as Double or Single floating point.

These datatypes will have rounding errors.

Use Decimal datatype instead or, even better, Currency if you are not interested in more than 4 decimal places

Yes, but regardless of defining the field -24.40/24.40=-1
Why does it give me an error in the calculation and is it possible to fix it?

 

[cheekybuddha]

-24.40/24.40=-1

What result do you expect from this calculation?

It looks right to me.

 

[Bonowox]

What result do you expect from this calculation?

It looks right to me.

Yes, you are right about that, but it gives me a result of -0.983870967741935
-24.40/24.40=-1 This is how I should get it

 

[ebs17]

Where are your numbers coming from?
Are you sure you have the full values in mind? Or are parts of the numbers hidden by formatting?

A deviation of about 1.6 percent is not solely due to the flow number problem.

 

[cheekybuddha]

Yes, but regardless of defining the field

Show how you have defined the fields

 

[Bonowox]

Dug_najamnina_yes Dug_najamnina_yes
This is what the query table looks like
Where: Expr1: [Uplatio]-[Zaduzen]
and Expr2: ([Expr1]/[Iznos])

KorisnikID	Zaduzen	Uplatio	Expr1	Izraz1	Expr2
Aziri (Tefik) Zaim	6.265,10 KM​	6.212,10 KM​	-53,00 KM​	53,00 KM​	-1​
Bajrami (Sejdija) Almir	6.818,70 KM​	6.487,50 KM​	-331,20 KM​	55,20 KM​	-6​
Baraković (Duran) Muškija	24,40 KM​	0,00 KM​	-24,40 KM​	24,40 KM​	-1​
Batlak (Adem) Samira	24,40 KM​	0,00 KM​	-24,40 KM​	24,40 KM​	-1​
Behram (Islam) Jusuf	24,40 KM​	0,00 KM​	-24,40 KM​	24,80 KM​	-0,983870967741935​
Berhamović (Husein) Jasmina	24,40 KM​	0,00 KM​	-24,40 KM​	24,40 KM​	-1​
Božović (Branko) Žarko	24,80 KM​	0,00 KM​	-24,80 KM​	28,40 KM​	-0,873239436619718​
Čelebić(Senad) Sanela	2.600,00 KM​	2.574,00 KM​	-26,00 KM​	26,00 KM​	-1​
Čevriz (Radoslav) Vasilija	3.828,90 KM​	3.797,90 KM​	-31,00 KM​	31,00 KM​	-1​
Ćatić (Meho) Alija	396,00 KM​	352,00 KM​	-44,00 KM​	44,00 KM​	-1​
Ćatović (Murat) Ismet	208,00 KM​	156,00 KM​	-52,00 KM​	26,00 KM​	-2​
Ćenan (Meho) Ramiza	24,40 KM​	0,00 KM​	-24,40 KM​	24,40 KM​	-1​
Ćenan (Mirzo) Erna	24,40 KM​	0,00 KM​	-24,40 KM​	24,40 KM​	-1​
Ćimić (Omer) Emir	3.024,00 KM​	3.052,00 KM​	28,00 KM​	28,00 KM​	1​
Ćupina (Murat) Šefika	24,80 KM​	0,00 KM​	-24,80 KM​	24,80 KM​	-1​
Ćurčin (Esad) Hafiza	275,20 KM​	206,40 KM​	-68,80 KM​	34,40 KM​	-2​

This is what the query table looks like
Where: Expr1: [Uplatio]-[Zaduzen]
and Expr2: ([Expr1]/[Iznos])
I have marked the correct calculation fields in green, and the incorrect ones in red
Thanks!

 

[ebs17]

This is what the query table looks like

My hint was about how the values are defined, not what they look like.

If you pour vinegar out of a champagne bottle, it's still vinegar. It won't be champagne. You see it, you taste it. But you have to turn on your senses.

 

[Bonowox]

My hint was about how the values are defined, not what they look like.

If you pour vinegar out of a champagne bottle, it's still vinegar. It won't be champagne. You see it, you taste it. But you have to turn on your senses.

Ok, but I'm curious why it shows a different result in these two cases, and the whole query is defined the same. Maybe I'm a bit boring but ....sorry I'm not clear

	24,40 KM	0,00 KM	-24,40 KM	24,40 KM	-1
	24,40 KM	0,00 KM	-24,40 KM	24,80 KM	-0,983870967741935

 

[The_Doc_Man]

First, your query info as shown in post #8 uses a different name than the column labels... Iznos vs. Izraz1 - so I can't tell if that should be the same or not. But assuming it is, you have that "Behram (Islam) Jusuf" row that you are complaining about, where you divide -24.40 / 24.80 - which according to my PC's calculator app is -0.9838709655419355, and I therefore don't see your problem. Then, from post 8 again, the line for "Božović (Branko) Žarko" shows -24.80 / 28.40 - which my PC calculator says is -0.8732394366197183

I would do some data checking.

 

[Bonowox]

First, your query info as shown in post #8 uses a different name than the column labels... Iznos vs. Izraz1 - so I can't tell if that should be the same or not. But assuming it is, you have that "Behram (Islam) Jusuf" row that you are complaining about, where you divide -24.40 / 24.80 - which according to my PC's calculator app is -0.9838709655419355, and I therefore don't see your problem. Then, from post 8 again, the line for "Božović (Branko) Žarko" shows -24.80 / 28.40 - which my PC calculator says is -0.8732394366197183

I would do some data checking.

Thank you very much my friend

 

[cheekybuddha]

Please check and let us know the datatypes of fields Uplatio, Zaduzen and Iznos in design view of your table.

Make sure you check the 'Field Size' property in the 'General' tab for each field.

 

[cheekybuddha]

The calculations in red look correct too:

-24,40 KM / 24,80 KM = -0,983870967741935
-24,80 KM / 28,40 KM = -0,873239436619718

 

[Pat Hartman]

As @cheekybuddha informed you back in post #2, Double and Single are prone to floating point errors because binary (how the data is stored in single/double) cannot always be converted cleanly to decimal (how the data is displayed). Unless you actually need all those decimal places, convert the data type to Currency or Decimal.

Here's an article that sheds some light on the issue.

Microsoft Access, Office/VBA, Excel, Visual Basic 6 and Visual Studio .NET Math Doesn't Add Up and Subtract Accurately

Subtration errors unrelated to floating point binary inaccuracies exist in all Windows programs such as Microsoft Access, Excel, VBA, VB6 and Visual Studio .NET

www.fmsinc.com