need help on finding what i missed!

hello all, i made a simple function , its pretty simple, but i dont know why a specific if block doesnt execute !
( the one which checks whether power is zero or not )
here is the code
and below is the screen shot i got from a sample input , i also mentioned what i expected to get instead of that

Code:

---

void Integral( double multipicant,double power,char sign[],int size,int operand_number)
{


        static int i =5,y=7,index = 0;

        int int_power = 0
        int condition = 0;

      if ( index == 5)
      {
              i = 5;
              y = 11;

      }
      if ( index >5 )
      {
              i+=1;
              y = 11;
      }



      int_power = (int)power;//used to check if power is zero ( because power is declared double , and it is not wise to use a double variable in an if statement,
                              //i converted it to int
      if ( 0 == int_power)
      {
              condition = 1;
              gotoxy(i,y+4);
              printf("%0.2f X ",fabs(multipicant));
              if ( index != operand_number-1 )
              {
                      gotoxy(i+5,y+4);

                      printf("%c",sign[index]);
              }

      }

      if ( power == -1)
      {
              condition = 0;

              gotoxy(i,y+4);
              printf("%0.2f * Ln(x)",fabs(multipicant));
              if ( index != operand_number-1 )
              {
                      gotoxy(i+14,y+4);

                      printf("%c",sign[index]);
              }

      }


      else
      {
              condition = 0;

              gotoxy(i+9,y+2);
              printf("%0.0f + 1",power);//the power of X
              gotoxy(i+7,y+3);
              printf("( X )");//print X
              gotoxy(i,y+4);
              printf("%0.2f *",fabs(multipicant));//multipicant
              printf(" ------");//division line
              gotoxy(i+6,y+5);
              printf(" %0.0f + 1",power);//power

              if ( index != operand_number-1 )
              {
                      gotoxy(i+14,y+4);
                      printf("%c",sign[index]);
              }
      }
      if (condition == 1)
      {
              i+=6;
      }
      else
      {
              i+=15;
      }

      index++;

        return ;
}

---

Sample sreenshot
http://master.huricane.googlepages.c...screenshot.JPG
tanx in advance

Code:

---

int_power = (int)power;

---

This is equivalent:

Code:

---

if ( 0 == (int)power)

---

Interesting that you observe "because power is declared double , and it is not wise to use a double variable in an if statement" then less than ten lines later:

Code:

---

if ( power == -1)

---

It is not *necessarily* bad to use a double in an if; more specifically, it is bad to use == to compare a double or a float to an integer such as -1 or 0. So you are correct to change the double, but you should do it with a simple cast and you should do it consistently.

Quote:

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Originally Posted by MK27

Code:

---

int_power = (int)power;

---

This is equivalent:

Code:

---

if ( 0 == (int)power)

---

Interesting that you observe "because power is declared double , and it is not wise to use a double variable in an if statement" then less than ten lines later:

Code:

---

if ( power == -1)

---

It is not *necessarily* bad to use a double in an if; more specifically, it is bad to use == to compare a double or a float to an integer such as -1 or 0. So you are correct to change the double, but you should do it with a simple cast and you should do it consistently.

---

tanx , i forgot that part!
but still i cant get the first if block to execute ! i m really confused! whats wrong with it?

If you want something to only happen if a condition is false, maybe you should put it in an else block? (The else block you have only corresponds to power == 1.)

>but i dont know why a specific if block doesnt execute
May be because the power value is not equal to 0. Try putting a print statment just above the if statment and see what does power varibale hold. Try debugging through that may. You might be able to pin point the error.

-ssharish

Quote:

---

Originally Posted by tabstop

If you want something to only happen if a condition is false, maybe you should put it in an else block? (The else block you have only corresponds to power == 1.)

---

yes, thats right, but as you see the first if block is placed before the second if .. else blocks, meaning if the " if statement condition is true then the block must execute.
i think i should add some more checks to the if's continuation conditions ,

Quote:

---

Originally Posted by ssharish2005

>but i dont know why a specific if block doesnt execute
May be because the power value is not equal to 0. Try putting a print statment just above the if statment and see what does power varibale hold. Try debugging through that may. You might be able to pin point the error.

-ssharish

---

i did it prints 0! i dont know either!

Quote:

---

Originally Posted by Masterx

yes, thats right, but as you see the first if block is placed before the second if .. else blocks, meaning if the " if statement condition is true then the block must execute.
i think i should add some more checks to the if's continuation conditions ,

---

What makes you think it doesn't get executed? It does, so far as I can tell, but it gets overwritten when the else part of the -1 check happens.

Pretty much very strange, try placing it this way

Code:

---

if( int_power == 0)

---

This shouldn't make any difference at all. But worth a try. Between would you be post the whole code, so that i could try as well on my system.

-ssharish

Quote:

---

Originally Posted by tabstop

What makes you think it doesn't get executed? It does, so far as I can tell, but it gets overwritten when the else part of the -1 check happens.

---

May be that right, he should probably use the if-elseif-else statment to skip the second if check.

-ssharish

i changed the last else to the following and it seems they are fine only if i dont use sth like "6x^-1" meaning a negative 1 power! if i do that ! the next zero powered expression would be altered! and the power would get incremented by one! which i have no idea whats happening to them!!

Code:

---

else if ( (-1!= (int)power )&& ( 0 != (int)power) )

---

1.sample one showing the correct output

sample 1.JPG - Free Image Hosting at TurboImageHost
2.sample 2 showing the messed up output!!
sample2.JPG - Free Image Hosting at TurboImageHost

Quote:

---

Originally Posted by ssharish2005

Pretty much very strange, try placing it this way

Code:

---

if( int_power == 0)

---

This shouldn't make any difference at all. But worth a try. Between would you be post the whole code, so that i could try as well on my system.

-ssharish

---

here it is . please note that where ever you see these words they mean
tavan = power
zarib = multipicant
. and the function in question is Integral() ;
and after download remove the .txt form the end of the file .
i translated some words to english , and now i think its fine .

any idea why this is happening ?
i also noticed that when that strange result happens, the power is actually 0 not 1.
i mean in this picture the power of 8 seems to be incremented by 1! but actually it is not like that! i used a printf! and saw that the power inside the block is still 0!
i dont know how that got there! with power 0! because of the condition check!

as you see everything before expressions like ( 6x^-1) is fine , and if blocks seem to work perfectly ! but when you use expressions with negative 1 (-1) power! this happens!

i finally figured it out . the problem was caused by :
if ( 0 == (int)power)
and the likes,
i changed the power to an integer value out of the blocks and used that integer_power as a check in if statement continuation condition . and it worked!
here is the final bit of code

Code:

---

double Integral( const double multipicant,const double power,char sign[],int size,int operand_number)
{

       
        double integral = 0.0;
        static int i =5,y=7,index = 0;
        int integer_power = 0;
        int condition = 0;

      if ( index == 5)
      {
              i = 5;
              y = 11;
              //condition = 1;
      }
      if ( index >5 )
      {
              i+=1;
              y = 11;
      }

      integer_power = power;

      if ( integer_power == 0 )
      {
//              gotoxy(35,30);
//              printf("\tp1%d",power);
              condition = 1;
              gotoxy(i,y+4);
              printf("%0.1fX",fabs(multipicant));
              if ( index != operand_number-1 )
              {
                      gotoxy(i+5,y+4);

                      printf("%c",sign[index]);
              }

      }

    else if ( integer_power == -1)
      {
              condition = 0;

              gotoxy(i,y+4);
              printf("%0.2f * Ln(x)",fabs(multipicant));
              if ( index != operand_number-1 )
              {
                      gotoxy(i+14,y+4);

                      printf("%c",sign[index]);
              }

      }


    else  if ( ( integer_power != -1 )&& ( integer_power != 0 ) )
      {
              condition = 0;


              gotoxy(i+9,y+2);
              printf("%0.0f + 1",power);//powere X
              gotoxy(i+7,y+3);
              printf("( X )");//khode X
              gotoxy(i,y+4);
              printf("%0.2f *",fabs(multipicant));//multipicant
              printf(" ------");//khate kasri
              gotoxy(i+6,y+5);
              printf(" %0.0f + 1",power);//poweremakhraj

              if ( index != operand_number-1 )
              {
                      gotoxy(i+14,y+4);
                      printf("%c",sign[index]);
              }
      }



      if (condition == 1)
      {
              i+=6;
      }
      else
      {
              i+=15;
      }

      index++;

        return integral;
}

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thankyou everyone for your helps