Similar in concept to Math.Abs() - I'm looking for a function that when given a positive integer will return the same integer. If given a negative, will return zero.So:
f(3) = 3
f(0) = 0
f(-3) = 0
Yes, this is simple enough to write on my own but I'm wondering if the .NET Math class already has this built in or if the same can be achieved by cleverly chaining a few Math.* calls?
Similar in concept to Math.Abs() - I'm looking for a function that when given a positive integer will return the same integer. If given a negative, will return zero.
So:
f(3) = 3
f(0) = 0
f(-3) = 0
Yes, this is simple enough to write on my own but I'm wondering if the .NET Math class already has this built in or if the same can be achieved by cleverly chaining a few Math.* calls?
I'm creating an emulator for a device to simulate wave forms. My challenge is that when I try to convert the output of the following code, I can't convert the Math.Sin's double output into byte values that lend themselves to the byte array format required by an existing graphing control as listed at bottom below. I''m not sure how to handle this when the sin function creates negative values but the byte values will need to be positive and basically 'shifted up' so that anything over 127 is negative. (0 - 255) unsigned. BitConverter.GetBytes has been suggested but THIS is the result of that attempt.
[Code]....
I am using delta plc. i want to send +1 to +30 & -1 to -30 numbers in 4 byte hex format(xxxx) in vb.net.
View 4 RepliesI am looking for a way to test an integer value to see if it is positive or negative so I can perform the required actions.
View 1 RepliesI have a visual basic .net application. It has a sql server database and a dataset for it. I have created an interface to the database (passing through my dataset) to add, delete, save etc records in a table.
The ID entry has identity specification:Yes and increment seed 1 When I add a record, instead of giving 1,2,3... as id in the textbox it produces -1,-2,-3 (Negative integers)
I have a program that calculates values of a function, say f, with respect to another variable, say L.I have an array of f(L), for L going from 0 to a given integer value, say t-1 in steps of a value i.I need to export the values of this function to an Excel spreadsheet in a given column, and to do this, I would like to re-index the function f, since i is much less than one, and so the following loop I use (see below) won't work:
For L = 0 To t - 1 Step i
Sheet.Cells(L, 1) = L
Sheet.Cells(L + 1, 2) = f(L)
Next L
The first code in the loop will essentially load the values of L itself, at which the function is defined and calculated, and the next line will load the values of the function at each value of L.Since the indexes of the row and columns in an excel spreadsheet only go in steps of 1, I need to convert the indexes of the function, or the indexes to which L is loaded, so that it would be scaled so that the first entry corresponds to L=0, but the next is L=i, but loaded into row number 2, etc.
retrieving the smallest integer from an image data (image data has a data type of byte which means that numbers range from zero to 255) but if smallest integer is zero than the next smallest number which
View 1 Repliesi'm dave mark.. im new to vb 2008.. i just have to have some question.. the problem is i have to input 10 integer number then after inputting the 10 number .. it will compute the sum, average and the smallest.. i have no problem with sum and average but in smallest number only... how to get the smallest number>>?
View 1 Replieswell i am having a couple of issues with this particular homework problem and this is my first programming class so there is probably quite a few mistakes well the homework problem is to take three double values entered by a user and display the largest and smallest using math.max and math.min and display the smallest and largest so i thought i could use a listbox and take the values that went to the listbox and assign variables to each so i can try to use each variable in the math.max and min but im not making it to far and i actually might be way off
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Is it possible to collect name of method, line, file etc in which exception occurred for logging purposes? I have heard its possible using System.Diagnostics.StackTrace but not sure how.
View 3 RepliesThese two TimeSpan are stored in the Database with 24hr format. No date, only TimeSpan.
Dim r As TimeSpan
Dim tsStart As TimeSpan
Dim tsEnd As TimeSpan
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Is there any TimeSpan method to get this right?
what I am trying to do is, when a ListView loads, for the code to check the entry in column one, and then return a message box if the column contains a specific date.
I am using:
SUB I DONT KNOW THE METHOD TO INSERT THIS INTO. I NEED IT CHECKED WHEN THE LISTVIEW CHANGES
If lvuPreviousJobs.SelectedItems(0).SubItems(2).Text = "31/12/9999" Then
{
MsgBox("TEST")
[code]....
is there a method check the number of records in data reader? like the count of rows. ?
View 2 RepliesI am working on this project and I am suppose to overload the method to allow strings instead of integer. Allow the user optionally add a thried string from a third text box. Okey I am trying to under stand this good. This is the code I have:
This is my overload class
Public Class OverloadEx
[CODE]........................
So with my overload class instead of integer I should put string there? If the user clicks the add button it will allow the user to add all 3 text boxes but when the user click the add string it will allow the user to add all three text boxes to string. So do I click the add string button to overload it to that one just like I did with the add?
I want to assign the value of the integer returned from the InStr method to a variable. So, If TextBox2.Text = "The Apple Pie" And TextBox1.Text = "App", I want the integer returned, which in this case would be 5, put into a variable, lets say its called 'VarString'.
So VarString (would) = 5.
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In VB.NET, it is entirely possible to pass an integer as a string parameter to a method without calling .ToString() - it's even possible to call .ToString without the ()'s. The code will run without a problem, VB will interpret the integer as a string without having been told to. In C#, these would cause compilation errors - you are required to call .ToString() and to call it correctly in that situation before it will compile. Is there a way to make the VB compilation process check for the same things as the C# compilation process? Would it be best practice in a mixed team to force this check?
View 3 RepliesThe code performs correctly when the input is an integer, but when I enter a character, the result is as though I've entered an integer. Can you tell me what's wrong with my TryParse statement?
Private Sub btnCompare_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCompare.Click
' Declare Local Variables
[CODE]...
I have a large number of methods and I need to call one of them, based on some integer. Of course I could just use a Select Case statement like so
[Code]...
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
[Code]....
ive got some simple problem i cant understand how to solve.
str(1) is an array and integer(or double, tried both)
a(1) is an array and integer (or double, tried both)
a(1) = a(1) + 1
Label1.Text = str(1) + a
the big part is where i get: operator '+' is not defined for types 'integer' and '1-dimensional array of integer'.why do i get that message and what does it mean? how do i make the code do what i want?
I faced an error when upgrading VB6 code to VB.NET. The error occurs at AddressOf WindowProc
AddressOf expression cannot be converted to 'Integer' because 'Integer' is not a delegate type
My declaration for SetWindowLong is:
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA"(
ByVal hWnd As Integer,
ByVal nIndex As Integer,[code]....
What is the reason for the error I get?
I'm trying to create a linked list of an array of integers. Why is the following implicit conversion required?
When I run the code that contains that conversion, I get the following error.
As a real-time data acquisition user control data (a packet of an array of bytes) arrives every second, is converted into an integer array and inserted into a linked list.
The most recently arrived data is painted as coordinates on a grid at the right of a PictureBox using Graphics.DrawLine (pen,X1,Y1,X2,Y2).
The oldest data (arriving 120 seconds ago) will be drawn at the leftmost portion of the Picturebox.
Why a linked list rather than a list? To display 120 views of time sequence data, the draw routine the most recently inserted node to a node that points to Nothing. How do I limit the length of the linked list to 120 nodes and always ensure that the last node points to Nothing?
Do While Not item Is Nothing
item = item.NextItem
Loop
I am a newbie in VB and I got a piece of code which can display the current running program. I need to use that in VB2005 and I got the below error message. Can anyone help how to fix it?[code]
View 18 RepliesI'm trying to convert a VB6 project to .NET, but I get problems with some callback functions, and the following message comes up: "AddressOf' expression cannot be converted to 'integer' because integer is not a delegate type" I've seen several solutions to similar problems like this, but I am not able to understand this issue with delegates.
After the conversion, the code look like this:
Declare Function vsmsgwSetDataPackageCB Lib "vsmsgwW.dll" (ByVal PACKAGE As Integer, ByRef arg As Integer) As Integer
Dim arginitP As Integer
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Which gives the error: Method 'Public Function PackageCB(HisNodeID As Integer, ByRef data() As Byte, ByVal length As Integer, ByRef arg As Integer) As Integer' does not have the same signature as delegate 'Delegate Function DelegatePackageCallback(hwnd As Integer, lparam As Integer) As Integer
I have a LINQ2Entity problem, I want to get the value, string, from a database, so I select FProducts.Serial_number, and to end the query, I do .ToDictionary. The problem is, it tells me that it doesn't have sufficient parameters, to convert ToDictionary. So I need something like select FProducts.Serial_number, Nothing). ToDictionary. Also FProducts.Serial_number, 0).ToDictionary doesn't work.
Sub GetStatistics(ByVal ProductNumbers As List(Of String), ByRef Passed As Integer, ByRef FailedProducts As List(Of String))
Passed = 0
FailedProducts = Nothing
[Code]...
this is for a BINGO game final project that I already turned in but this just bugged me that I could not get the sorting figured out. I am trying to get this to sort the random numbers in to columns under the correct letters but I keep getting the error Operator '>=' is not defined for types '1-dimensional array of Integer' and 'Integer' under the line:
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I am new to EF Linq and I have been struggling with this query for a few days. From reading this forum, I have managed to get this far:
Dim noPic = (From f In myEntities.FriendLists
Where (f.UserID = Profile.ID)
Select f.FriendID).Except(From g In myEntities.GuestLists
Where g.EventID = _id
Select g.FriendID)
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I am trying to get everybody from the FriendList who is not already on the GuestList to display in a Repeater control. After reading the forum I was able to append .First() to noPic at the myNoPic declaration and finally get a result but that only gave me the first element. Does anybody have any advice on how to accomplish this?
Why doesn't CDate(integer) work where integer has format of YYYYMMDD ?and why won't this stupid site let me submit such a short question when I have nothing else to add except some waffle at the end
View 2 Repliesam trying to get the following code to work:
Dim testString As String
testString = cbbxStartDt.SelectedValue.ToString("yyyyMMdd")
when doing so the code is being stoped and I get "InvalidCastException" error emssage:
Conversion from string "yyyyMMdd" to type 'Integer' is not valid.
If I do the following, then it works:
Dim testDate As Date
Dim testString As String
testDate = cbbxStartDt.SelectedValue
testString = testDate.ToString("yyyyMMdd")
This, returns the desired value: "20110103"
NB:
cbbxStartDt.SelectedValue.ToString returns: "03/01/2011 00:00:00"
So would it be possible that the problem comes from of the "time bit" : "00:00:00"?if, so is it the parsetime function which would allow to take into account only the time bit value of the combobox?