C / C++ / MFC Discussion Boards

Re: learn how to learn

jinjiashan7-Oct-09 22:10

jinjiashan

7-Oct-09 22:10

Calculate p-value of chisquare test in C

enthusiastic4777-Oct-09 13:33

enthusiastic477

7-Oct-09 13:33

I am working on a huge program one of whose part is chi-square test. Actually, I have generated a dataset by implementing some other concepts and I need to implement chi-square test on that data.

Could anyone teach me how to calculate the P-value from a chi-square value ? It would be great if you have some source code or some link.

Thanks.

Re: Calculate p-value of chisquare test in C

CPallini7-Oct-09 20:59

CPallini

7-Oct-09 20:59

It looks interesting: why don't you write the code (you're a developer, right?)? You may also write an article about.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: Calculate p-value of chisquare test in C

enthusiastic4778-Oct-09 6:47

enthusiastic477

8-Oct-09 6:47

Good Answer Big Grin | :-D

.. Although I have almost tried everything I thought using my utmost potential..

I would definitely write an article if I could write the code..

I am really in trouble.. Please help!!

Re: Calculate p-value of chisquare test in C

CPallini8-Oct-09 10:25

CPallini

8-Oct-09 10:25

What is your doubt about? Do you clearly understand the statistics but have troubles performing the C implementation? The opposite? Both? What have you coded so far (i.e. what is you data set? Have you attempted a chi-square computation?)?

Smile | :)

Re: Calculate p-value of chisquare test in C

enthusiastic4779-Oct-09 2:24

enthusiastic477

9-Oct-09 2:24

Yes I have already computed the chi-square computation. Now I need to find out the value in C, which can be done in excel as chidist(Chisquare_value, degree_of_freedom).. Actually I have a tree structure which contains the data and I need to find the p-value for each and every node of the tree (as said above, I have already calculated the chi-square value fir each and every node).

Thanks,

Re: Calculate p-value of chisquare test in C

CPallini9-Oct-09 12:25

CPallini

9-Oct-09 12:25

What you probably need is a numerical algorithm for computing the incomplete Gamma function. See section 6.2 of "Numerical Recipes in C" [^].
Smile | :)

How to change color of menu bar of dialog?

includeh107-Oct-09 10:50

includeh10

7-Oct-09 10:50

How to change color of menu bar of dialog?

Re: How to change color of menu bar of dialog?

«_Superman_»7-Oct-09 13:46

«_Superman_»

7-Oct-09 13:46

Get the handle to the menu using GetMenu[^] or GetSubMenu[^].
Call SetMenuInfo[^] to set the brush used to paint the menu.
Set the required brush color in the hbrBack member of the MENUINFO[^] structure.
Finally call DrawMenuBar[^] to redraw the menu.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Using FormatMessage function

dipuks7-Oct-09 8:57

dipuks

7-Oct-09 8:57

Hello

Looking at different examples online, it all says the lpBuffer parameter has to be
a LPVOID (LPSTR).

Is it possible to allocate a fixed memory buffer like a,

char pBuffer[512];

In that case do i need to call LocalFree() function?

Can anyone show me how to use that? I wanted to make sure i allocate the memory on compile time rather than on run time.

Re: Using FormatMessage function

Nemanja Trifunovic7-Oct-09 9:11

Nemanja Trifunovic

7-Oct-09 9:11

If you don't set dwFlags to include FORMAT_MESSAGE_ALLOCATE_BUFFER you can allocate the buffer yourself on the stack and not call LocalFree() to release it.

On another hand, how do you know the message will fit into 512 bytes?

utf8-cpp

Re: Using FormatMessage function

wangningyu7-Oct-09 17:31

wangningyu

7-Oct-09 17:31

I agree with Nemanja Trifunovic.In accordance with his idea,you can refer to the following codes:

LPVOID   lpMsgBuf; <br />
FormatMessage(   <br />
        FORMAT_MESSAGE_ALLOCATE_BUFFER   |   <br />
        FORMAT_MESSAGE_FROM_SYSTEM       |   <br />
        FORMAT_MESSAGE_IGNORE_INSERTS, <br />
        NULL, <br />
        GetLastError(), <br />
        MAKELANGID(LANG_NEUTRAL,   SUBLANG_DEFAULT),   //   Default language <br />
        (LPTSTR)   &lpMsgBuf, <br />
        0, <br />
        NULL   <br />
); <br />
// Process any inserts in lpMsgBuf. <br />
// ... <br />
// Display the string. <br />
MessageBox(NULL, (LPCTSTR)lpMsgBuf, "Error", MB_OK | MB_ICONINFORMATION); <br />
<br />
// Free the buffer. <br />
LocalFree(lpMsgBuf);

Producer consumer problem

sandeep80147-Oct-09 8:31

sandeep8014

7-Oct-09 8:31

Producer-consumer problem on a circular buffer. Multiple producer and multiple consumer threads may be running concurrently using either semaphores or a combination of mutexes and condition variables.

Re: Producer consumer problem

Maximilien7-Oct-09 9:28

Maximilien

7-Oct-09 9:28

yes.

This signature was proudly tested on animals.

Re: Producer consumer problem

CPallini7-Oct-09 10:11

CPallini

7-Oct-09 10:11

Yes and the kernel is preemptive, and today is the 'dumb people making pointless posts' day. Roll eyes | :rolleyes:

Re: Producer consumer problem

Rajesh R Subramanian8-Oct-09 6:40

Rajesh R Subramanian

8-Oct-09 6:40

I would actually even try a SRW Lock, but then since this case might require FIFO (SRW Locks are not FIFO, and the algorithm isn't "fair" either), a CRITICAL_SECTION is the best option. I'm assuming that this is all happening within the same process, but if not, you could use a Mutex.

It is a crappy thing, but it's life -^ Carlo Pallini

programming using named pipes

sandeep80147-Oct-09 8:29

sandeep8014

7-Oct-09 8:29

A program (server) that reads a single number as input, searches the file for a line with the input integer as the serial number and writes the proverb or the short quotation as output. If the number is not found in the file, the program should return some default message of your choice.
A program (client) which asks the user to enter a number and outputs the same
Is it possible to connect the client and the server programs with a named pipe so that the client can display the output from the server program.

Re: programming using named pipes

CPallini7-Oct-09 10:05

CPallini

7-Oct-09 10:05

Yes, it is possible. Smile | :)

Columns with checkboxes

burslem20017-Oct-09 4:45

burslem2001

7-Oct-09 4:45

Hello,

I have a question concerning VC++ and columns and checkboxes. This I'm assuming
is a common hurdle to jump when building a GUI.

I want to to have a graphical interface that shows a list of columns.
The first column, describes the item the following columns could A,B,C etc but are
"checkbox" columns that will profile the item in the first column.

I went down the merry path of looking into CListControl in MFC that has a column
and by setting the style to CHECKBOX you can have a single item with one checkbox,
nice to know. Not what I need.

Datagrid looks like that is what I need, but I dont see this in MFC.
Can somebody point me to an example and even tell me if this is what I need.

Thanks in advance,
Garyc

Re: Columns with checkboxes

CPallini7-Oct-09 6:29

CPallini

7-Oct-09 6:29

Have a look at this article [^].
Smile | :)

Re: Columns with checkboxes

burslem20017-Oct-09 7:34

burslem2001

7-Oct-09 7:34

Much appreciated. I will have a gander at this.

Re: Columns with checkboxes

David Crow7-Oct-09 11:00

David Crow

7-Oct-09 11:00

I've used XListCtrl, from here at CP, many times.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Re: Columns with checkboxes

Rolf Kristensen8-Oct-09 9:04

Rolf Kristensen

8-Oct-09 9:04

You can use the subitem-image to display the checkbox. Just copy the state-images to the official image-list, and react to mouse-click on the subitem-image to change the checkbox.

I have implemented this on CGridListCtrlEx - Grid Control Based on CListCtrl[^]

Two groupbutton with radio buttons on same dialog

johnjitu7-Oct-09 3:59

johnjitu

7-Oct-09 3:59

Hello

Every body

Please help me ,i am stuck with this problem

I have created two groupboxes and with radiobuttons on the same dialog .My problem is that the functions of radiobutton of one group is mixed with another and i cannot operate them indepentl

Thansk in advance

Re: Two groupbutton with radio buttons on same dialog

Code-o-mat7-Oct-09 4:06

Code-o-mat

7-Oct-09 4:06

I'm not sure i understand you correctly but in resource editor, give the "Group" (WS_GROUP) style to the first radio button in both of your "radiobutton-sets".

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.