In the vb function 'round', I want to be able to round to one digit after the decimal. It seems like in the following code:
round([SHAPE_Area]/10000, 1) & " ha"
Where I want to round to to one place after the decimal, if the value for that palce after the decimal is 0, then it rounds to a whole number (i.e. 1 instead of 1.0) I would like it to round to 1.0. The [SHAPE_Area] field is of type 'Double'. I'm not sure if that has any significance to the vb rounding function and how it rounds.
The number is rounded correctly. The number 1 is the same thing as the number 1.0.
What you want to do is formatting the number:
Dim formatted As String = String.Format("{0:N1} ha", SHAPE_Area)
Use .ToString() with the correct Format String instead:
([SHAPE_Area]/10000).ToString("F1") & " ha"
Related
I'm new to VB.net coding i would like to know how to round of a decimal number to the nearest integer
Eg. X= (5-2/2) = 1.5
but I need only as 1.
Thank you.
You can use the integer division operator if you just want to discard any remainder:
Dim resultValue As Integer = (5-2) \ 2
Note that this is one of the differences between VB.NET and C#, in C# the normal division operator will always apply integer division, so discard the remainder.
You have other options:
resultValue = CInt(Math.Floor((5-2) / 2))
resultValue = CInt(Math.Round((5-2) / 2, MidpointRounding.ToZero))
Try this:
Math.Round( (5-2)/2, 0)
..and look into the options for the overload with the MidpointRounding param, which you can set to influence rounding when the result ends with .5. Here are some of the available options:
Math.Round((5 - 2) / 2, MidpointRounding.AwayFromZero)
Math.Round((5 - 2) / 2, MidpointRounding.ToEven)
Check the documentation (or trial & error) to see which best suits your needs.
Or if you always want either the integer below or the integer above, then also check out Math.Floor and Math.Ceiling functions.
I think you can use the floor function. For example, double floor(double x);, the floor function returns the largest integer that is smaller than or equal to x.
Vb.net has a decimal data type.
Unlike normal double or floating points, decimal data type can store values like 0.1
Now say I have a variable like precision.
Say precision is 8
So basically I want to do
Protected Overridable Sub setPairsPricesStep2(decimalPrecission As Long, Optional base As String = "", Optional quote As String = "")
If decimalPrecission = 8 Then
Return
End If
Dim price = 10D ^ (-decimalPrecission)
setPairsPriceStep1(price, base, quote)
End Sub
There is a problem there
the result of Dim price = 10D ^ (-decimalPrecission) is double, not decimal. I can convert it to decimal but then I will lost the precission.
So what is the right way to do it? Should I just use for next but that's hardly elegant.
It's simple
I want a function that given precisions give decimal value.
For example, if precision is 1 I got 0.1. If precision is 5, I got 0.00001
I ended up doing this
For i = 1 To decimalPrecission
price *= 0.1D
Next
But surely there is a better way
Update:
Per comment, I tried
Dim e = 10D ^ -5
Dim e1 = 10D ^ -5L
The type of e and e1 are both double.
I suppose I can do Cdec(e). But then it means I have lost accuracy because normal double cannot store .1 correctly.
I want a function that given precisions give decimal value.
For example, if precision is 1 I got 0.1. If precision is 5, I got 0.00001
Since you are working with the Decimal type, the simplest way to get this result is to use the Decimal constructor that allows you to specify the scale factor.
Public Sub New (lo As Integer, mid As Integer, hi As Integer, isNegative As Boolean, scale As Byte)
From the Remarks section of the above referenced documentation,
The binary representation of a Decimal number consists of a 1-bit sign, a 96-bit integer number, and a scaling factor used to divide the integer number and specify what portion of it is a decimal fraction. The scaling factor is implicitly the number 10 raised to an exponent ranging from 0 to 28.
So you can see that if take the value of one divided by 10 to the first power, the result is 0.1. Likewise, one divided by 10 to the fifth power, the result is 0.00001.
The lo, mid, and hi arguments in the constructor could be obtained by uisng the [Decimal.GetBits Method](Decimal.GetBits Method), but for this simple case, I chose to hard code the values for the value of one stored as a decimal.
To obtain a value of 0.1D:
New Decimal(1, 0, 0, False, 1)
To obtain a value of 0.00001D:
New Decimal(1, 0, 0, False, 5)
Dim stringrepresentation = "1E-" + decimalPrecission.ToString
Dim price = Decimal.Parse(stringrepresentation, System.Globalization.NumberStyles.AllowExponent)
This is what I basically did. Basically I created a string 1E-5, for example, and use decimal.parse to get the decimal
I wonder if there is a better way but I have no idea.
Actually Jimy ways may work too but rounded to a number
I try to write the result of the division of the number 5991 by 2987 in vb.net, without rounding the decimal or floating point, strictly equal to 2.005691329092 on 12 digits after the decimal point. The decimal part (0.05691329092) is also noted 17/2987 in scientific notation. My tests always led me to 2.005691329093 rounding!
2 17/2987
Actual value is correct, issue is how to format value to display it as expected.
There are no built-in method, but you can multiply value by required amount of digits after decimal point and truncate it.
Dim value As Double = 5991.0 / 2987.0
value = Math.Truncate(value * Math.Pow(10, 12)) / Math.Pow(10, 12)
Console.WriteLine($"Result: {value:F12}")
How do you access the decimal part of a number in MS Access? More specifically I want only the component after the decimal point, but not including the decimal point. This must also work for all whole numbers. I've seen this answered for other SQL engines, but they don't work in Access. I can't be much more specific than this because of the sensitive nature of what I'm actually working on.
For example given the following numbers the input is on the left and the output is on the right. Output can be either text or a number.
Source Correct Incorrect1 Incorrect2
10.0 0 0.0 .0
3.14159 14159 0.14159 .14159
45.65 65 0.65 .65
173.0 0 0.0 .0
143.15 15 0.15 .15
If I was using C# the following code would give me what I want:
private string getDecimalComponent(double input)
{
String strInput = input.ToString();
if (strInput.Contains('.'))
{
return strInput.Split('.')[1];
}
else
{
return "0";
}
}
Subtract the integer portion of the value.
Example:
4.25 - Int(4.25) = 0.25
Or, as a sample SQL expression:
SELECT
[myDecimalNumber],
[myDecimalNumber] - Int([myDecimalNumber]) as [rightOfDecimal]
FROM tableA
Something like:
SELECT 3.14%1 AS mycolumn from mytable
Depends on the circumstance. If this is, for instance, in a textbox, you can use InStr to find the decimal, and then use the Mid() function to get the number after it. If it's part of an arithmetic equation, then I would use the Int() function and subtract one number from the other to get the difference.
If you can elaborate on how it's being used, and in what context, I can edit my answer to give you more specifics.
EDIT: After more info came to light, try this:
Public Function GetParts(Temp1 as Double)
Temp2 = Int(Temp1)
Temp3 = Mid(Temp1, InStr(Temp1, ".") + 1)
MsgBox Temp2
MsgBox Temp3
End Function
A stable solution producing String containing decimal places from Double.
SELECT DecimalPlaces(MyColumn) FROM MyTable
where the above user-defined function contains the following code:
Function DecimalPlaces(ByVal value As Double) As String
Dim intPartLen As String
intPartLen = Len(CStr(CInt(Abs(value))))
If Len(CStr(Abs(value))) > intPartLen Then
DecimalPlaces = Mid(CStr(Abs(value)), intPartLen + 2)
Else
DecimalPlaces = "0"
End If
End Function
It avoids common mistakes, so it is
locale-independent - works with any decimal separator (it only assumes it is a single character)
preserves precision - avoids subtraction, takes the result only from string representation
Note: those Abs() calls are really required (hint: -0.1)
Why vb prints out 1??? when d is a double aproximation to 1? shoudnt be 0.99999 or something similar? what if I really need the float value? and how could I print it?
Dim d As Double
For i = 1 To 10
d = d + 0.1
Next
MsgBox(d)
Console.WriteLine(d)
thanks
When using MsgBox or Console.WriteLine, double.ToString() is called in order to convert the double to a string.
By default this uses the G format specifier.
The general ("G") format specifier converts a number to the most compact of either fixed-point or scientific notation, depending on the type of the number and whether a precision specifier is present. The precision specifier defines the maximum number of significant digits that can appear in the result string. If the precision specifier is omitted or zero, the type of the number determines the default precision, as indicated in the following table.
And:
However, if the number is a Decimal and the precision specifier is omitted, fixed-point notation is always used and trailing zeros are preserved.
When converting the infinite 0.9999999.... to a string, since it goes forever, rounding occurs, this results in 1.
A simple test is to run this:
MsgBox((0.9999999999999999999999999).ToString())