C / C++ / MFC Discussion Boards

CPallini5-Jun-20 0:04

5-Jun-20 0:04

Your code is wrong because you are printing the b matrix while you're updating it (you are printing 'not yet updated' items).
Try

#include <stdio.h>
  

int main()
{
  int a[3][3],b[3][3],i,j;
  for(i=0;i<3;i++)
    for(j=0;j<3;j++)
      scanf("%d",&a[i][j]);

  for(i=0;i<3;i++)
  {
    for(j=0;j<3;j++)
    {
      printf("%d ",a[i][j]);
    }
    printf("\n");
  }
  for(i=0;i<3;i++)
  {
    for(j=0;j<3;j++)
    {
      b[j][i]=a[i][j];
    }
    printf("\n");
  }
  for(i=0;i<3;i++)
  {
    for(j=0;j<3;j++)
    {
      printf("%d ",b[i][j]);
    }
    printf("\n");
  }
  return 0;
}

Re: Transpose of a matrix

jeron15-Jun-20 4:53

jeron1

5-Jun-20 4:53

b[j][i]=a[i][j];
printf("%d ",b[i][j]);

So you wanted to print the value of b[i][j] after you updated b[j][i]?

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How to draw a realtime XY plot in MFC

manoharbalu1-Jun-20 22:31

manoharbalu

1-Jun-20 22:31

How to draw a realtime XY plot in MFC.

I have an existing MFC application in which there are many tags that changes continuously.
I have to show the value of 2 tags which changes dynamically. I have to plot an XY plot for the tags in a separate dialog or window in the existing MFC application.

Please suggest me some easiest or quickest ways of doing the above task.

Re: How to draw a realtime XY plot in MFC

Victor Nijegorodov1-Jun-20 22:40

Victor Nijegorodov

1-Jun-20 22:40

Well the Microsoft Scribble sample would be a good start.

Re: How to draw a realtime XY plot in MFC

Richard MacCutchan2-Jun-20 0:15

Richard MacCutchan

2-Jun-20 0:15

I remember trying to learn MFC with that back in 1992. OMG | :OMG:

Re: How to draw a realtime XY plot in MFC

Victor Nijegorodov2-Jun-20 0:24

Victor Nijegorodov

2-Jun-20 0:24

Re: How to draw a realtime XY plot in MFC

CPallini5-Jun-20 0:33

CPallini

5-Jun-20 0:33

You might also search for a CodeProject article on the topic[^].

Re: How to draw a realtime XY plot in MFC

charlieg7-Jun-20 7:29

charlieg

7-Jun-20 7:29

There are many good articles about drawing in mfc - which is really pretty much Win32. Rather than have that magical moment where you get it running and it flickers constantly, make sure to look into double buffering with a bitmap.

Charlie Gilley
<italic>Stuck in a dysfunctional matrix from which I must escape...

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Random numbers

Calin Negru1-Jun-20 21:03

Calin Negru

1-Jun-20 21:03

How do you generate random numbers in C++? I C# I had to use a seed and set some range limits/boundaries.

.

modified 2-Jun-20 3:21am.

Re: Random numbers

_Flaviu1-Jun-20 21:26

_Flaviu

1-Jun-20 21:26

With rand - C++ Reference[^] function. You can find there few examples.

Re: Random numbers

Calin Negru2-Jun-20 5:34

Calin Negru

2-Jun-20 5:34

Thanks

Re: Random numbers

Joe Woodbury2-Jun-20 11:21

Joe Woodbury

2-Jun-20 11:21

Do NOT use rand. See <random> - C++ Reference[^]

Re: Random numbers

Richard MacCutchan1-Jun-20 22:25

Richard MacCutchan

1-Jun-20 22:25

A google search would have found the answer quicker than it takes to open a question here. Please try doing a bit of research first.

Re: Random numbers

Calin Negru2-Jun-20 4:10

Calin Negru

2-Jun-20 4:10

k, I`ll keep that in mind next time I post. I still believe in learning by human interaction though.

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modified 2-Jun-20 11:12am.

Re: Random numbers

Richard MacCutchan2-Jun-20 5:22

Richard MacCutchan

2-Jun-20 5:22

Keep it in mind before you post. And if you really want to learn a language there are many useful books and tutorials you can make use of.

Re: Random numbers

Calin Negru2-Jun-20 6:52

Calin Negru

2-Jun-20 6:52

Re: Random numbers

CPallini2-Jun-20 20:16

CPallini

2-Jun-20 20:16

You may use either the legacy rand()[^] function (with the srand one you might provide the seed), or the classes provided by the 'new' random header[^]. The latter is more sophisticated and has a somewhat more difficult interface. You might look at code samples, though, for instance, see the code in this page[^].

Re: Random numbers

Calin Negru3-Jun-20 20:50

Calin Negru

3-Jun-20 20:50

Thank you CPallini

my name is Calin Negru, I also post on GameDev.net

modified 20-Jun-20 3:14am.

Re: Random numbers

CPallini3-Jun-20 20:53

CPallini

3-Jun-20 20:53

You are welcome.

Return Statement in C| when I used print just after if condition it gave me "Equal multiple times" but when i used return statement it game me single time?

Member 148492461-Jun-20 10:17

Member 14849246

1-Jun-20 10:17

void main()
{char name[50],came[50];int i;
gets(name);
gets(came);
for(i=0;name[i]||came[i];i++)
{int d=name[i]-came[i];
if(d==0)
return printf("Equal");
else return printf("Unequal");
}
}

Re: Return Statement in C| when I used print just after if condition it gave me "Equal multiple times" but when i used return statement it game me single time?

jeron11-Jun-20 10:45

jeron1

1-Jun-20 10:45

Using return where you do, exits the current function you are in, in this case it is main(). So you are exiting the program when you call return.

Re: Return Statement in C| when I used print just after if condition it gave me "Equal multiple times" but when i used return statement it game me single time?

Richard MacCutchan1-Jun-20 20:54

Richard MacCutchan

1-Jun-20 20:54

You should read through every section of Organization of the C Language Reference | Microsoft Docs[^]. You will learn much faster than by posting questions here.

I could not understand loop testcondition understanding| rest program runs fine

Member 1484924631-May-20 8:55

Member 14849246

31-May-20 8:55

<pre>#include<stdio.h>
void main()
{char name[40];
printf("Enter the string:");
gets(name);
char ch = ' ';
int i,count=0;
for(i=0;name[i];i++)
{if(name[i]==' ')
count++;
}
printf("Number of words is %d",(count)+1);
}</pre>

-- modified 31-May-20 15:08pm.

Re: I could not understand loop testcondition understanding| rest program runs fine

Greg Utas31-May-20 9:40

Greg Utas

31-May-20 9:40

This is something I hate, but it's idiomatic. A C string ends with the character NUL, whose ASCII value is 0, which is equivalent to false. So the loop ends when the character NUL (usually written as '\0') is encountered. The check is equivalent to

name[i] != '\0'

but some people hate typing so much that they write this kind of thing.

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modified 31-May-20 15:49pm.

Re: I could not understand loop testcondition understanding| rest program runs fine

Richard MacCutchan31-May-20 21:58

Richard MacCutchan

31-May-20 21:58

The for statement breaks down as three individual expressions:

C++

for(set; while; do) :
//
// set : perform this or these expressions first: multiple expressions must be separated by commas
// while : repeat the loop while this expression equates to true
// do : perform this or these expressions at the end of each loop

Note that any of these expressions (or indeed all of them) may be blank.
In your code the expression in the while part is name[i], which means while name[i] is true, or rather while name[i] is not equal to zero. Strings in C are (or should be) terminated with a zero character (NULL), so the expression will be true as long as the character in question is not the terminating NULL.

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