C / C++ / MFC

how to create sin() and log() functions of myown?

1-Sep-07 9:11

Oh yeah, good One Smile | :)

Bookmarked.

Thanks,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

includeh101-Sep-07 6:12

includeh10

1-Sep-07 6:12

In my app, i need large float data, so i create a class for it.

but existing functions, such as sin(.), log(.) ..., are all use double, so I have to create similar functions to suit my large float numbers.

How to create my own sin(.), log(.) etc?

Re: how to create sin() and log() functions of myown?

El Corazon1-Sep-07 8:18

El Corazon

1-Sep-07 8:18

includeh10 wrote:
so I have to create similar functions to suit my large float numbers.

http://www.netlib.org/cephes/[^] already exists.

But if you really want to write your own, pull the sources for GNU compilers standard math libraries, and extend them to long double.

_________________________
Asu no koto o ieba, tenjo de nezumi ga warau.
Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)

Re: how to create sin() and log() functions of myown?

Stephen Hewitt3-Sep-07 15:11

Stephen Hewitt

3-Sep-07 15:11

One method is to use Taylor Polynomials[^].

Steve

CAsyncSocket problem

__yash__1-Sep-07 6:02

__yash__

1-Sep-07 6:02

Hi people,
I m facing a problem with sockets.
My application connects to a device that has an IP and a port. If i switch on the device first and then my application i m able to establish consistent communication between them; however if i run the application first and then turn on the device it doesnt connect then.
P.S: I m using a Connect-button on the front-end to connect

Please help.

Button Connect function is as follows:
m_sConnectSocket1.Create();
m_sConnectSocket1.Connect(m_strIP1,m_iPort1);

Re: CAsyncSocket problem

Mark Salsbery1-Sep-07 7:15

1-Sep-07 7:15

You should check error codes...

m_sConnectSocket1.Create();
if (!m_sConnectSocket1.Connect(m_strIP1,m_iPort1))
{
   int sockerrcode = m_sConnectSocket1.GetLastError();

   if (sockerrcode == WSAEWOULDBLOCK)
   {
      // OnConnect() will be called
      //   look for errors there as well
   }
   else
   {
      // What's the WSAxxxxx error??
       //  (OnConnect() will NOT be called)
    }
}
...

void MySocketClass::OnConnect(int nErrorCode)
{
   if (nErrorCode != 0)
   {
      // Connect failed - what's the WSAxxxx error??
      return;
   }
...
}

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: CAsyncSocket problem

__yash__1-Sep-07 23:27

__yash__

1-Sep-07 23:27

I get error code 10035-WSAEWOULDBLOCK, that is when it connects but if i run the apllication first and then the device i get errorcode 10022 WSAEINVAL
If OnConnect() event is triggered shouldnt the error code be 10056?? Or, conversely, what error code(s) are/is possible if OnConnect() gets triggered??
By your code it seems a successful connection would produce an err-code of WOULDBLOCK.

Actually what i m doing in my new code is i keep trying to connect till the error code is 10056 or a timeout of 2 seconds, whichever is first. This i guess could be a wrong procedure. But it always works if i start the device first.

Re: CAsyncSocket problem

Mark Salsbery2-Sep-07 9:12

Re: Catching exceptions MFC

2-Sep-07 9:12

The possible error codes for Connect() are listed in the documentation for
CAsyncSocket::Connect() and also can be found in the Winsock docs:

connect() (Windows Sockets 2)[^]

Any time you use asynchronous sockets, an error of WSAEWOULDBLOCK
means the operation has NOT completed yet so no error info is available
at that time. To find out if the operation succeeded or not, you need
to get the results in whatever asynchronous completion method you're using.
In your case, that's in an overridden OnConnect() method.

yashveer wrote:
Actually what i m doing in my new code is i keep trying to connect till the error code is 10056

That's not a proper way to check for a successful connection. Either there's an error or there's not.
You can find that out using the example code (or similar) that I posted previously.

And please use "WSAEISCONN" instead of "10056" when posting error codes.
I don't have them all memorized so I have to look them up. They'll make your code more
readable as well Poke tongue | ;-P

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Catching exceptions MFC

barbarini1-Sep-07 5:34

barbarini

1-Sep-07 5:34

I have a problem. I am trying to catch some exception and I still haven't succeded. I tried with very simple example but still isn't working. Cakb someon help. Here is the code;
try
{
int a=5, b=0, c;
c = a/b;
}
catch (CException* e)
{
MessageBox("Division by zero exception!");
}

My program ends with error without executing the code in catch block.?????

lznix charles1-Sep-07 6:08

lznix charles

1-Sep-07 6:08

try
{
int a=5, b=0, c;
c = a/b;
}
catch (...)
{
MessageBox("Division by zero exception!");
}

Re: Catching exceptions MFC

Hamid_RT1-Sep-07 6:47

Hamid_RT

1-Sep-07 6:47

You can use of this code

try
{
int a=5, b=0, c;
if (b == 0)
throw int();
    c = a/b;
}
catch (int)
{
    MessageBox(_T("Division by zero exception!"));
}

Re: Catching exceptions MFC

Gary R. Wheeler2-Sep-07 4:17

Gary R. Wheeler

2-Sep-07 4:17

See this[^] article on MSDN about exceptions. The first example illustrates handling divide-by-zero handling.

Software Zen: delete this;

Fold With Us![^]

Regarding DLL Creation

SimplyCool1-Sep-07 5:02

SimplyCool

1-Sep-07 5:02

Can I be able to convert VC++ builtin header files to DLL file.

As an experiment i tried in math.h but failed to create a dll.As build log said unable to register dll and dll was present no where.
And also how can i export my constants.Is that also possible?

Am I lacking a perfect picture of the whole thing DLL is doing?Help me please

Re: Regarding DLL Creation

Gary R. Wheeler2-Sep-07 4:24

Gary R. Wheeler

2-Sep-07 4:24

You can't 'convert' header files into DLL's. A header file describes the contents of a DLL. A given header file may describe only part of a DLL. For example, math.h describes math-related functions in the C runtime library. The actual DLL in this case is MSVCRT.dll, which is usually installed in C:\Windows\System32.

You shouldn't need to do anything to create this DLL; it's installed as part of Windows, since so many Windows-supplied applications and components use it.

If you have general questions on creating and using DLL's, this[^] is an entire section of Code Project devoted to the subject.

Software Zen: delete this;

Fold With Us![^]

How to Use Picture Control

GauranG Shah1-Sep-07 3:10

GauranG Shah

1-Sep-07 3:10

Can Anybody Tell me How to use picture Control.

I need to dynamically load the image on that picture Control.

Using Win32 Application

Hamid_RT1-Sep-07 4:54

Hamid_RT

1-Sep-07 4:54

Can you more explain about picture control? for load images see OleLoadPicture and if your images are bmp you can use of LoadImage of course if your program was MFC you could use of CImage class if you want to assign a image to a control you can use of CStatic control on the toolbox when you insert this control to your program it has a function SetBitmap(with hbitmap handle) that you can show your image.

Mark Salsbery1-Sep-07 7:29

1-Sep-07 7:29

A picture control is a static control with the SS_BITMAP, SS_ICON, or
SS_ENHMETAFILE style.

To set the control's image you can use the STM_SETIMAGE message
(I'll assume you're using the SS_BITMAP style):

HBITMAP hNewBitmap = ...;

HBITMAP hPreviousBitmap = ::SendMessage(hwndPicConrol, STM_SETIMAGE, IMAGE_BITMAP,  (LPARAM)hNewBitmap);

Where is the image coming from that you want to set to the control?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

GauranG Shah2-Sep-07 18:44

GauranG Shah

2-Sep-07 18:44

Thnk you for reply. But how do i get the handle to picture control. i.e hwndPictureControl

Mark Salsbery3-Sep-07 8:04

load GIF file in the tourbo c++

3-Sep-07 8:04

If you created the control with CreateWindow[Ex]() then the API will return the handle.

If the control is on a dialog created from a dialog resource, the you can use GetDlgItem()
to get a handle to a dialog control given its ID.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

mahdiehIR1-Sep-07 2:28

mahdiehIR

1-Sep-07 2:28

hi all
I want load GIF file in the touro c++ but I don't know how I can
do its
plz hellp me
thanks alot
bye

Nishad S1-Sep-07 2:37

Nishad S

1-Sep-07 2:37

mahideh wrote:
in the touro c++

Are you using the windows APIs?

- NS -

mahdiehIR1-Sep-07 3:33

mahdiehIR

1-Sep-07 3:33

I should use from GIF format file for load its in to DOS
but I don't know how I use from LZW code for decode data of image and draw image in consul

Hamid_RT1-Sep-07 4:56

Hamid_RT

1-Sep-07 4:56

For see detaily of graphic formats and how to read and open them see CXImage class on the codeproject maybe it will be helpful for you.

Mark Salsbery1-Sep-07 7:40