I am calculating the average of an array(double) using a known (smaller) array of integers, which contains the indices for the larger array to give the values for the average. Below is the function:
'
'NumLoops = Ubound(LookupList)+1 !
' i always >0
Function Mean(ByRef Y() As Double, ByRef LookupList() As Integer, ByVal NumLoops As Integer) As Double
Dim res As Double
[Code] .....
Stand alone performance (through a win32 project) form is very good for my project. e.g. a Y() = 50000 entries, LookupList=1000 entries, calculating the mean 1000 times take about 5 ms.
That beats a c++ function accessed through a rcw quite easily (takes >300ms). However, when I plumb this function into a larger project the performance drops off significantly, taking (typically) 50ms for the same test. Also if (say) I make Y bigger (say, 100 000 elements) with everything else the same I see a tiny overhead in the stand alone test (of order 1 ms), yet I see a close to linear increase in the calculation time in the larger project. The larger project is not so big (a few MB) as to make we worry about resource constraints.
I have a program in where I need to loop though the entire dataset.datatable. I takes a long time. What is the alternative I can use to do the some job but faster?
In my winform application, I have 2 datatables, both contains 37000 rows. Table 1 has 171 columns and Table 2 has 4 columns. A While loop runs to update values in Table 1 from Table 2 for 4 columns. A For loop runs inside While twice to update values. It takes more than 5 min to do so. which i think should be a task of 5 seconds.
I wrote a serializer (to Byte Array) for dictionaries that have a string key, but an object of some sort as its value.I've never implemented a generic type in a function or used a delegate before, so I'm a bit concerned about this being significantly slower than writing a serialization function for a specific type of Dictionary (Dictionary(Of String, MyClass) for example)Should this code be significantly slower due to the use of the generic type or the delegate?
[code]...
It works, and I could loop it and compare it to a more static Dictionary serializer, but I'm more concerned about when I start using this for a lot of different String/Object dictionary combinations, and it'll take me a long time to write a bunch of static dictionary serializers (that's what I'm hoping to avoid in the first place)edit: simplified intro text
An in-line table valued function in SSMS takes about 6 seconds to return 11088 records. The same function in VB .Net 4.0 using TableAdapters.InputTableAdapter.GetData (Created with data set designer) takes about 15 minutes complete.Both are executed from the same workstation.Why does this discrepancy exist?
A common mathematical function is the Factorial function. The factorial function takes an integer input of "n" that is greater than or equal to 1 and computes n* (n-1) * ... * 2 * 1. In mathematical texts, factorial is denoted with an exclamation point, as in n!.For this exercise,write a function called Factorial that takes a single Integer input and returns an Integer corresponding to the factorial of the inputted parameter. To help get you started, your function will look like this:
[code]...
After you have written this Factorial function, add a Page_Load event handler that calls the function, displaying on the ASP.NET web page the values of 1! through 5!.Hint: The Factorial function will need to contain a looping construct from 1 to n, where, at each iteration, a variable is multiplied by the value of the looping variable.Now I'm not asking anyone to solve this for me but rather if you could help me understand how I should go about it. I'm not really understanding how I would loop and increment this function. Would I make the variables 1! through 5! equal to the given values and have them called to the equation and then loop it and increment it as so? I'm not even sure I'm thinking this out correctly.
I am fairly new to VB and I am struggling with not using the Reverse string.I need to take a persons name from a text box and print the name backwards in a label using lop and the MID function.I have this, but it doesn't use the MID Function, how would I change it.
Private Sub convertButton_Click(sender As System.Object, e As System.EventArgs) Handles convertButton.Click, ClearToolStripMenuItem.Click Dim Name As String = ""
VB.NET Dim iString As String If My.Settings.IPBank.Count = 30 Then MsgBox("You alredy have the maximum amount of IP Addresses stored, delete one to add another.", MsgBoxStyle.Information, "Program Error")
[Code]...
I want it to check all of the items in the my.settings.ipbank which is a stringcollection. Before it adds and if it already exists in my.settings.ipbank then i want it not to add it. But it just adds when i run it. And then once its added it says: "Collection was modified; enumeration operation may not execute." But also before i run it. There is a warning saying: Function 'AddTo_IPBank' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used. Is this something to do with it? I think i have the Next in the wrong place .
I'm using a DO interation to loop a function I'm using to test for internet connectivity. The code is working fine, except that when one of the tests is satisfied the loop stops. I want this to continue in the background while the program is running. How can I get this to work?
Private Sub checkInternet() Dim InetChecker As Boolean InetChecker = CheckForInternetConnection() Do While LabelCount.Text <> "" Thread.Sleep(10) [Code] .....
I'm looping through items in a listview. For each item, it deletes a file containing information stored and re-writes it with new information from the listview item.
I am descending all the directories of my C drive to get a complete list of all extensions.When I get to: C:Windows.oldDocuments and SettingsAll UsersApplication Data
the program goes into a loop: C:Windows.oldDocuments and SettingsAll UsersApplication Data Application Data Application Data until the path exceeds maximum length (248 characters for the directory).
I would like to be able to save to a db and send task to email or as text msg for instance nevermind that.. I have two variables of type ArrayList they are "_mList1" , "_mList2" and "_mList3"
_mList1 stores the list of Telephonenumbers , _mList2 stores the list of StaffIDs and _mList3 Some concatenated string.
theses variable lists will hold some data in runtime as explained and i would like to use them to populate a DB table again mentioned
I should use the Timer_Tick function, to loop a data read from a COM port. The object i call uses a method that closes the thread after a fixed timeout.
obj.Read(N byte) //--> if no data come within 500ms close the thread
My question is: considering that the Timer_Tick function will be called every (for example) 100ms, How long does the total execution last? Timer_tick time + Thread Timeout (100ms + 500 ms = 600ms) or just the Timer_Tick time (100ms) causing the anticipated thread closure/crash?
I am using the following code to get distance between two propertys. The problem i am having is each Distance Calculation is being obliterated and I am only geting back the last Calculation instead of each calculation/distance
Langauge level hours German 2 50 French 3 40 English 1 60
[code]....
I want to loop through the records based on language and other conditions and then pass the current selected record to a different function.So I have the following mixture of actual code and psudo code. I need help with converting the psudo code to actual code, please. I am finding it difficult to do so.
Here is what I have:
Private sub mainp() Dim oslcConnection As New SQLite.SQLiteConnection Dim oslcCommand As SQLite.SQLiteCommand Dim langs() As String = {"German", "French", "English"}
Makes the following statement about the code below:
**"The computer evaluates the loop condition in the Do...Loop statment to determine whether the loop instructions should be processed. In this case, the inputsales <> String.Empty condition compares the contenst of the input sales variable to the String.Empty value. As you know the String.Empty value represents a zero length, or empty, string if the inputsales variable is empty, the loop condition evaluates to True and the computer process the loop instructions. *If on the other hand the inputsales variable is not empty, the loop condition evaluates to false and the computer skips over the loop instructions.
Based on the code I think it is the opposite: ...that while the inputsales value is not empty it should evaluate to true and process the loop and if it is empty it should evaluate to false and skip the loop?
i just got 1 question how do u create a (in excel ) variable table (database) inside a function which could be called for filling and reading through "for to next" loop module
I want to make an numerical integration method with takes in an analytic function and integrate it over a specific interval. For the numerical integration procedure I want to use some procedures in nr.com. The problem is that these are programmed in C++ and they uses functors to pass a function to the integration method. How can I do this in VB 2010?
I want to initialize the function (i.e. set a=1,b=0 for function y(x)=a*x+b) and then pass the function to the integration method. Then when the integration method call the function it only calls the function with one parameter (i.e. x since a,b is already set)
What is the best way to do this in VB2010?I want to make a general integration method where I can pass any single valued function and integration limits.
I have just started using VB, and from what I have found so far it seems like the tools you have is
- to us a delegate for the function - to use a lambda expression for the function - send a pointer/adressOf - to create a function class/structure and submit this to the function
As for now I am most inclined to create a function-class. But I am not really sure how.F.ex. I make different classes for each "uniqe function" I want to integrate, but how can I pass them to the integration function when I need to specify the argument type in the integration-function-call?This seems like a basic problem which applies to many Math operations, so I think it would be very useful to clarify this.
I'm trying to undersatnd the syntax of calling a funciton and it seem confusing when I'm using a web service in ASP.net. Maybe this question should be in an ASP forum, but it is a VB question. This simple web service allows you to type in your name and it response with an alert box with you name.
My question is, How can you call a function with 2 arguments when the function is only defined for one. I understand that the second argument is actually a method that handling the respons, but how can you interchange function arguments for methods and how do you know that there are methods for
I am constructing a program, i am new to Visual Basic, but i have past programming experience. I was wondering if anyone knew how to form a loop that could...lets say calculate the answer when two numbers are added together,and it would repeat this thousands of times, etc. And if there is a way, would it be possible to calculate the time taken to complete this loop.
I have written a function that gets the alexa ranking of a given url, now this function works perfectly but I want to loop through a ListView of urls and grab the alexa rank of each item (url) with my function.The code works great if I put a MessageBox in the loop to test that the function is returning a value but when I remove the MessageBox the loop does not work.I need it to loop through adding each result without a MessageBox stop in each loop.
vb For Each Item In ListView1.Items Dim result As Integer result = GetAlexaRank(Item.Text)
I am running windows vista with 1gb memory and 2ghz proccessor. What would be the best FREE version of .NET to use for best performance? Its been years since I have done any PC programming and I would like to do a little bit =]
The upper picture is the output of a Unix task. The lower picture is what I have in VB. Enumerating tasks is not difficult however the rest it is because it's not documented anywhere.
What am I interested in if I want to get 64-bit performance data?
