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Pass by reference problem

Discussion in 'C' started by askmewhy25, Mar 4, 2010.

  1. askmewhy25

    askmewhy25 New Member

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    I am making a program that solves for Standard Deviation unfortunately my program
    doesn't print correct answer but just prints the 1.#J or the infinity error if I am right

    I can't figure out what is the problem with my codes can someone help me to debug..
    because I don't have enough knowledge about pass by reference

    here is the code

    Code:
    //Prototypes
    double Standard();
    double EvalStandard(double mean,double calc,int b,double data[]){
      int a;
      double sum,sd;
      for(a=0;a<b;a++){
        sum=sum+data[a];
        }
      mean=sum/a;
      for(a=0;a<b;a++){
        calc+=pow((data[a]-mean),2);
        }
      sd=sqrt(calc/(b-1));
      return sd;
    }
    
    
    //Function
    //Standard Deviation Function
    double Standard(){
      int SA,a,b;
      double sum=0,data[10],mean,calc,sd;
      char error[128];
      
      do{
        system("cls");
        printf("Standard Deviation\n\n");
        printf("Enter the Number of Data (max. 10): ");
        scanf("%s",&error);
        b=atoi(error);
        if(b>10||b==0){
          system("cls");
          printf("Invalid input. Please try again!!!\n");
          printf("Please press the spacebar to continue!!\n");
          getche();
          }
        }while(b>10||b==0);
      for(a=0;a<b;a++){
        printf("Enter the Actual Values of Data %d: ", a+1);
        scanf("%s",&error);
        data[a]=atof(error);
        }
      if(b==1){
        printf("The Standard Deviation the Data is 0\n");
        printf("Please press the spacebar to continue!!");
        getche();
        }
      else{
        sd=EvalStandard(mean,calc,b,data);
        printf("The Standard Deviation the Data is %.2lf\n",sd);
        printf("Please press the spacebar to continue!!");
        getche();
      }
    }
    
     
    Last edited: Mar 4, 2010
  2. karthigayan

    karthigayan New Member

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    I have checked your code in linux environment and I inserted some of the lines to manage the flow.

    When I execute I got the error "undefined reference to `sqrt'".Because in the program you used a math.h function.

    Then I compile the program using -lm option.It is for the math.h functions.

    cc -lm test_program.c

    Then I ran the program It got work.

    Code:
    #include<stdio.h>
    #include<math.h>
    //Prototypes
    double Standard();
    double EvalStandard(double mean,double calc,int b,double data[]){
      int a;
      double sum,sd;
      for(a=0;a<b;a++){
        sum=sum+data[a];
        }
      mean=sum/a;
      for(a=0;a<b;a++){
        calc+=pow((data[a]-mean),2);
        }
      sd=sqrt(calc/(b-1));
      return sd;
    }
    
    
    //Function
    //Standard Deviation Function
    double Standard(){
      int SA,a,b;
      double sum=0,data[10],mean,calc,sd;
      char error[128];
      char c;
      while(1)
      {
      do{
        system("clear");
        printf("Standard Deviation\n\n");
        printf("Enter the Number of Data (max. 10): ");
        scanf("%s",&error);
        b=atoi(error);
        if(b>10||b==0){
          system("clear");
          printf("Invalid input. Please try again!!!\n");
          printf("Please press the spacebar to continue!!\n");
          c=getchar();
          }
        }while(b>10||b==0);
      for(a=0;a<b;a++){
        printf("Enter the Actual Values of Data %d: ", a+1);
        scanf("%s",&error);
        data[a]=atof(error);
        }
      if(b==1){
        printf("The Standard Deviation the Data is 0\n");
        printf("Please press the spacebar to continue!!");
        getchar();
        if((c=getchar())!=' ')
                break;
    
        }
      else{
        sd=EvalStandard(mean,calc,b,data);
        printf("The Standard Deviation the Data is %.2lf\n",sd);
        printf("Please press the spacebar to continue!!");
        getchar();
        if((c=getchar())!=' ')
                break;
      }
      }
    }
    
    main()
    {
            Standard();
    }
    
     

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