Passing arrays to function

[mrb2129]

Hello everyone, I am trying to create an array of 200 random numbers and find the max value within specified upper and lower limits using a programmer defined functions. I get a debug error pop up on the screen which stops the program halfway through. The array is run but I cannot find the max. I'm wondering if I'm calling the function wrong. Below is the code I'm trying to run followed by the functions and library.

/*This program will create an array of random numbers between 500 and 0*/
/*This program will calculate the result of programmer defined functions*/
#include <iostream>
#include <cstdlib>
#include "Statfunctions.h"

using namespace std;

//Define variable names

int main()
{
int thearray[200], upper = 500, lower = 0, i;
for (i = 0; i <= 200; i++)
{
thearray[i] = rand() % (upper - lower + 1) + lower;
cout << thearray[i] << endl;
}
double max;
max = maxval(0, i);
}

-------------
#include <cmath>
using namespace std;

/*---------------------------------------------------------*/
/* This function returns the maximum */
/* value in teh array x with n elements. */

double maxval(const double x[], int n)
{
// Declare local objects.
double maxVal;

// Determine maximum value in the array.
maxVal = x[0];
for (int k = 1; k<n; ++k)
{
if (x[k] > maxVal)
maxVal = x[k];
}

// Return maximum value.
return maxVal;
}
/*---------------------------------------------------------*/
/* This function returns the minimum */
/* value in teh array x with n elements. */

double minval(const double x[], int n)
{
// Declare local objects.
double min_x;

// Determine minimum value in the array.
min_x = x[0];
for (int k = 1; k <= n - 1; ++k)
{
if (x[k] < min_x)
min_x = x[k];
}

// Return minimum value.
return min_x;
}
/*---------------------------------------------------------*/
/* This function returns the average or */
/* mean value of an array with n elements. */

double mean(const double x[], int n)
{
// Declare and initialize objects.
double sum(0);

// Determine mean value.
for (int k = 0; k<n; ++k)
{
sum += x[k];
}

// Return mean value.
return sum / n;
}
/*---------------------------------------------------------*/
/* This function returns the median */
/* value in an array x with n elements. */
/* The values in x are assumed to be ordered. */

double median(const double x[], int n)
{
// Declare objects.
double median_x;
int k;

// Determine median value.
k = floor(double(n) / 2);
if (n % 2 != 0)
median_x = x[k];
else
median_x = (x[k - 1] + x[k]) / 2;

// Return median value.
return median_x;
}
/*---------------------------------------------------------*/
/* This function returns the variance */
/* of an array with n elements. */

// Function prototype.
double mean(const double x[], int n);

double variance(const double x[], int n) // Function header.
{
// Declare objects.
double sum(0), mu;

// Determine variance.
mu = mean(x, n);
for (int k = 0; k<n; ++k)
{
sum += (x[k] - mu)*(x[k] - mu);
}

// Return variance.
return sum / (n - 1);
}
/*---------------------------------------------------------*/
/* This function returns the standard deviation */
/* of an array with n elements. */

// Function prototype.
double variance(const double x[], int n);

double std_dev(const double x[], int n) // Function header.
{

// Return standard deviation.
return sqrt(variance(x, n));
}
/*---------------------------------------------------------*/

-------------------
#include <cmath>
double maxval(const double x[], int n);
double minval(const double x[], int n);
double mean(const double x[], int n);
double median(const double x[], int n);
double variance(const double x[], int n);
double std_dev(const double x[], int n);

[MiiNiPaa]

//Function is defined as
double maxval(const double x[], int n)
//You calling it as
max = maxval(0, i);

That is the problem.

[mrb2129]

Ok, well, how do I call the function then because nothing I've tried works...

[MikeyBoy]

You've defined the function to take an array as its first argument. Why not try, y'know, passing in an array? Instead of 0, which will be interpreted as a NULL pointer.