Re: HOW TO DISTINGUISE POINTS OF LINES AND CURVES ??? - .NET (Core and Framework) Discussion Boards

I'm not sure I understand the problem.

Surely, if you're drawing the lines and curves you know which points you've used for each, and can save that information.

There are three kinds of people in the world - those who can count and those who can't...

hiii

molesworth

The drawing of polygon is in very later stage.

My aim is by visualizing the neighbouring point how can i under stand these set of points will be in straight line and those set of points will be in curve????

Ah, I think I understand. You want to draw a line when the points are on a line (or close to it) and a curve of some sort otherwise.

The simplest way that comes to mind is to calculate the slope of the line segments between pairs of points and if all the slopes are equal (within some reasonable limits) then the points lie on a straight line.

There are three kinds of people in the world - those who can count and those who can't...

hi molesworth
thanx for reply.

hi molesworth
thanx for reply

But there may be lots of line in various direction..in that case how the slope is same for every line??

It seems I've misunderstood your problem. I was guessing from the description that you had a number of points (x,y) and wanted to draw lines through them. If the points lie on a straight line, then you want to draw only that straight line through them, but if they don't then you want to draw a curve through them.

Perhaps you can explain with a bit more detail what you are trying to do.

There are three kinds of people in the world - those who can count and those who can't...

Mr.molesworth
thanx for reply

yes u are right that i have number of points(x,y) near about 1000.If i plot all these points in graph paper then it looks like a polygon.And polygon is combination of lots of curve and lines. And in curve there are lot of combination of small length of straight line.Basicaly if i join two point it becomes straight line.
And in curve the each small straight lines bend very slightly and it appears in graph like a curve. But i dont want to plot these point on the graph paper.

Only i have set of points(x,y).

How can i calculate that some set of points will be used for drawing one or more than one curve and other set of points will be used for drawing the line or lines..

awaiting for ur reply....

TARAK NATH ROY wrote:
i have number of points(x,y) near about 1000.If i plot all these points in graph paper then it looks like a polygon.And polygon is combination of lots of curve and lines

OK, I think I understand a bit better now. You have a large list of points, and want to draw a figure from them, using straight lines and curves to best fit the shape. Although to be technically correct, a polygon is a shape made of only straight lines, I get what you mean.

So, you need to go through the list, finding the sections which are best drawn as straight lines, and which are best as curves. My previous suggestion about matching slopes is probably still a reasonable way to try, but over limited ranges of points.

If you calculate the slope between points (Xn, Yn) and (Xn+1, Yn+1) as (Yn+1 - Yn) / (Xn+1 - Xn) then you can compare the slope values as you step through the list (increasing n).

If consecutive slopes are equal, or better, if the difference between them is less than some small constant, then the group of points are all very close to being a straight line. If you get a change in slope, greater than your limit value, then you've entered a curve region.

As you go through the points you can either copy them to separate line and curve lists, or possibly note the indices where the type of line changes.

Drawing the straight lines is easy, however you may have to look at your data more closely to find the best curve drawing method to give a good match.

Here's a rough pseudo-code version of what I'm describing above :-

lastSlope = 0;

for (int n=0; n<numPoints; ++n)
{
    // need to check for dX == 0  and handle array overrun
    slope = (Y[n+1] - Y[n]) / (X[n+1] - X[n]);

    if (abs(slope - lastSlope) < smallValue)
    {
        // now in straight line region
        // add points to straight line list
    }
    else
    {
        // now in curve region
        // add points to curve list
    }

    lastSlope = slope;
}

I hope that helps you a bit... Smile | :)

There are three kinds of people in the world - those who can count and those who can't...

As an alternative to my last post, you could always try just drawing straight lines between the points, and seeing what it looks like.

I have an audio waveform display in the project I'm currently working on, and I just join all the sample values with straight lines, which looks fine since there are so many of them in the view.

You might get away with just doing that...

There are three kinds of people in the world - those who can count and those who can't...

After installing WSE 3.0 Runtime, the option for WSE setting is not available when you right click on the slolution.Even there is no "WSESettingsVS3.Addin" file available at "C:\Documents and Settings\All Users\Application Data\Microsoft\MSEnvShared\Addins " location. Does anybody know the reason behind this ? Confused | :confused:

Dear Friends.
Actually i need to debug my setup projects. which is is Release mode.
i can able to debug my projects in Debug mode.
whats is wrong in my coding
public override void Install(System.Collections.IDictionary stateSaver)
{
try
{
System.Diagnostics.Debugger.Launch();
//----
// My Stuff here
//----

}
catch (Exception ex)
{

}
}

And also i tried this instead of
System.Diagnostics.Debugger.Launch();
#if DEBUG
if (System.Diagnostics.Debugger.IsAttached)
System.Diagnostics.Debugger.Break();
#endif

Please tell me, the solution to debug my project in Release mode.

Seems you don't have a clear idea about the Debugging API. What you exactly want to do? Tracing any problem happens during the setup? ...you can use logging for that.

Moim Hossain
R&D Project Manager
BlueCielo ECM Solutions BV

Dear Friends.

How to run .net application on Macintosh operating system. .net WMI works on Macintosh Operating System or not.

Please help me resolved this problem.

Piyush Vardhan Singh
p_vardhan14@rediffmail.com
Eventure Technology
http://holyschoolofvaranasi.blogspot.com
http://holytravelsofvaranasi.blogspot.com

What you need is The Mono Project, which should do what you are looking for.

There are three kinds of people in the world - those who can count and those who can't...

but The Mono Project not support all namespace of .net for example:-Wmi,Drive Info and Etc

Piyush Vardhan Singh
p_vardhan14@rediffmail.com
Eventure Technology
http://holyschoolofvaranasi.blogspot.com
http://holytravelsofvaranasi.blogspot.com

Ah, sorry - I didn't take in the reference to WMI in your original post.

Mono is an ongoing project, and continually being added to. Unfortunately, if you need something that isn't currently implemented there's not much you can do. I'm surprised DriveInfo isn't in yet though.

As far as I know Mono is the only real way to get .Net apps running under OS-X. Perhaps you can write work-arounds using the features which are implemented?

edit : DriveInfo is implemented in Mono. Perhaps the features of WMI that you need are also available. It would be worth checking.

There are three kinds of people in the world - those who can count and those who can't...

[Message Deleted]

Hi,

seems like you have a null object inside ExecuteOrder() at BookStoreWebService.asmx.cs:line 60
you should fix that.

Smile | :)

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Hmmm | :|

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Hello everyone ,

I have an issue i.e, I am using crystal report(version 11 release 2) in my windows applications developed in vb.net (2005)and sql server(2005) as backend . In one of the forms i placed one reportviewer control,

crystal report taking long time for preview & print(nearly 2 minute) .
please any one help me to getout of this

Dim rpt As New CrystalReport1() 'The report you created.
        Dim myConnection As SqlConnection
        Dim MyCommand As New SqlCommand()
        Dim myDA As New SqlDataAdapter()
        Dim myDS As New Dataset1() 'The DataSet you created.

        Try

            myConnection = New SqlConnection("Data Source=localhost;Integrated Security=SSPI;" & _
                                             "Initial Catalog=northwind;")
            MyCommand.Connection = myConnection
            MyCommand.CommandText = "SELECT * FROM Customers"
            MyCommand.CommandType = CommandType.Text
            myDA.SelectCommand = MyCommand

            myDA.Fill(myDS, "Customers")
            rpt.SetDataSource(myDS)
            CrystalReportViewer1.ReportSource = rpt

        Catch Excep As Exception
            MessageBox.Show(Excep.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try

Advance thnx.

You're selecting everything from the customers table to add to the report. Is this where the bottleneck is? Do you need to select all of this data?

thnx for Ur replay.
I am taking one record only using where condition,but that time also this report taking more time for first preview,next preview its taking less time compare to first preview.

If your database connection has not been pooled, then the first preview will take a lot longer than the second time where it's pulled from the pool.

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As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

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Is the column you are referencing in your where clause defined by an index ?

Use the "show execution plan" option in query analyzer to make sure the query is not doing table scans.

Optimize the query first, then the report should work fine.

Hi,
I m manjari.let me tell u the problem while doing my work in my company.when ever a person click the print option to print a document it should detect the person and that time instead of print dialog box our window should display with username and password.if valid then it will goes to print spool.I hv done the program after going to print spool it already detect the person but i want before goin to print spool it should detct.anybody plz help me as soon as possible.
thanks,
regards,
manjari

How i will design a a form in windows service to print a document.