I need help please

I looked everywhere but didn't find clear help x.x

I need to make a program using gaussian function, which is also called bell curve. I need the program to receive the mean and standard deviaton and then request 4 points which are values for x and then display in a tabular format the x and the corresponding f(x) values. And all calculations must be done in a separate function and all results to be displayed in main.

Can anyone please help?

Hi, have you seen this component?

http://www.codecogs.com/d-ox/stats/dists/continuous/normal/pdf.php

This is basically a component which returns the value of the gaussian function f(x) for given values of the mean and standard deviation. This module also contains some example code which may give you a hint on how to write your algorithm.

Please let me know if you have further questions.

Yes, that does help. One problem I had was figuring out how to do the calculations, that does show it pretty well.

Now getting x and f(x) tabular format is another problem, I'll try to look for that.

er wait, there is a library there from codecogs but this program has to be used with other people, then won't every person have to use that library but they won't have it...

I see what you mean but since this component is licensed both under GPL and commercial terms, it will be no problem downloading a version for each person that will be using it. Just make sure the .h header file will be in the right folder so that the #include will work.

Have you managed to display the results in tabular format? I have come up with the following piece of code which I believe is an implementation of your algorithm.

#include <stdio.h>
#include <codecogs/stats/dists/continuous/normal/pdf.h>
 
// the number of points 
#define N 4
 
int main()
{
  double mean;
  printf("mean = "); scanf("%lf", &mean);
 
  double stdev;
  printf("standard deviation = "); scanf("%lf", &stdev);
 
  double x[N];
  printf("\nthe given points:\n\n");
  for (int i = 0; i < N; i++)
  {
    printf("x[%d] = ", i+1);
    scanf("%lf", &x[i]);
  }
 
  printf("\nfunction values:\n\n");
  for (int i = 0; i < N; i++)
    printf("x = %lf\tf(x)= %lf\n", 
    x[i], Stats::Dists::Continuous::Normal::PDF(x[i]));
  printf("\n");
 
  return 0;
}

Notice that you may change the number of points through the #define at the beginning of the code. Looking forward to your reply.

Sorry, just forgot to include two essential parameters when making a call to the PDF function. This block of code, right after reading the user data

printf("\nfunction values:\n\n");
  for (int i = 0; i < N; i++)
    printf("x = %lf\tf(x)= %lf\n",
    x[i], Stats::Dists::Continuous::Normal::PDF(x[i]));
  printf("\n");

should obviously be changed into

printf("\nfunction values:\n\n");
  for (int i = 0; i < N; i++)
    printf("x = %lf\tf(x)= %lf\n",
    x[i], Stats::Dists::Continuous::Normal::PDF(x[i], mean, stdev));
  printf("\n");

You shouldn't have received any compiler errors since this function assigns mean = 0 and stdev = 1 implicitly, as for the standard normal PDF.