Find the bugs and syntax errors in this program (Language: C) below.

Please also correct them (please write comments of what you did to correct each one) so that the program runs correctly :)

The source code:

/*---------------------------------------------------- File: plotPoly This program plots a polynomial function. ------------------------------------------------------*/ #include #include "gng1106plplot.h" #define N 50 // number of points for plotting #define X_IX 0 // index to row of x values #define FX_IX 1 // index to row of f(x) values #define MAX_COEFF 11 // max number of coefficiencts, degree 10 double poly(double, double[], int ); int getCoefficients(double *, double *, double []); void calculatePoints(int np, double points[][np], double, double, int, double []); void plot(int n, double[][n]); double getMin(double *, int ); double getMax(double *, int ); /*----------------------------------------------------- Function: main Description: Call getCoefficients to fill in the array of coefficients and get range for plotting the polynomial. Calls calculate points to fill in the 2D array with polynomial points. Then calls plot to plot the polynomial. -------------------------------------------------------*/ int main() { //Variables declarations double coefficients[MAX_COEFF]; // Largest degree is MAX_COEEF-1 double points[2][N]; // for storing fx/x values double start, end; // Start and end x values double n; // number of coefficients given by user

// Get User input n = getCoefficients(start, end, coefficients); // Compute the points calculatePoints(N, points, start, end, n, coefficients); // Plot plot(N, points); return 0; } /*---------------------------------------------------------- Function: getCoefficients Parameters: sPtr - pointer for storing start value ePtr - pointer for storing end value coeff - reference to array of coefficients Returns: number of coefficients given by user Description: Requests from the user the coeffients for defining the polynomial (the number must be less than MAX_COEFF) and the start/end values for plotting the polynomial. -----------------------------------------------------------*/ int getCoefficients(double *sPtr, double *ePtr, double coeff[]) { int n; // coefficient number char answer; // First lets prompt for the coeffients printf("Please provide up to 11 coefficients (polynomial of degre 10) "); n = 0; do { printf("Coefficient c[%d]: ",n); scanf("%lf",&coeff[n]); n = n + 1; printf("Do you wish to add another coefficient (y/n)? "); fflush(stdin); scanf("%c", &answer); } while(answer != 'y' && n <= MAX_COEFF); // Get range do { printf("Give value for start: "); scanf("%lf",sPtr); printf("Give value for end: "); scanf("%lf",ePtr); if(*ePtr <= *sPtr) printf("End value must be greater than start value "); } while(*ePtr <= *sPtr); return(n); // returns number of coefficients given by user }

/*---------------------------------------------------------- Function: calculatePoints Parameters: np - number of points to compute (store in points 2D array) points - reference to 2D array for storing the points start/end - start and end range for computing points nc - number of coefficents in the coeffient array coeff - reference to array of coefficients Description: Fills in the points array with np points with x varying between start and end. Parameters nc/coeff defines the polynomial function for calculating f(x) using calls to poly. -----------------------------------------------------------*/ void calculatePoints(int np, double points[][np], double start, double end, int nc, double coeff[]) { double inc; // for incrementing x int ix; // for indexing into 2D colunms // Calculate function points inc = (end-start)/(np-1); // Comput the first point points[X_IX][0] = start; points[FX_IX][0] = poly(points[X_IX][0],coeff,nc); // Compute all other points for(ix = 1; ix < N; ix = ix + 1) { points[X_IX][ix] = points[X_IX][ix -1] + inc; points[FX_IX][ix] = poly(points[X_IX][ix],coeff,nc); } } /*---------------------------------------------------------- Function: poly Parameters: x - x value of polynomial c - reference to array of coefficients n - number of coefficients Returns: value y of polynomial Description: Calculates the value of the polynomial, f(x), for the given value of x. The polynomial is:

y = c[0] x^n-1 + c[1] x^n-2 + ... c[n-2] x + c[n-1

The numerical method presented in Lab 7 is applied. -----------------------------------------------------------*/ double poly(double x, double c[], int n) { double fx; int coeffIx; fx = c[0]; for(coeffIx = 0; coeffIx < n; coeffIx = coeffIx+1) fx = fx*x + c[coeffIx]; return(fx); } /*------------------------------------------------- Function: plot() Parameters: n: number of points in the 2D array points: pointer 2D array that contains points. Description: Initialises the plot. The following values in the referenced structure are used to setup the plot: points[X_IX][0], points[X_IX][n-1] - assume that x values are sequential minfx, maxfx - vertical axis range (add 10% to min/max value) Sets up white background and black forground colors. Then plots the curve accessed using xPtr and yPtr. -------------------------------------------------*/ void plot(int n, double points[][n]) { double minfx, maxfx; double range; // range of vertical axix // Setup plot configuration plsdev("wingcc"); // Sets device to wingcc - CodeBlocks compiler // Initialise the plot plinit(); // Configure the axis and labels plwidth(3); // select the width of the pen // Find range for axis minfx = getMin(points[FX_IX], n); maxfx = getMax(points[FX_IX], n); range = maxfx - minfx; // the width of the range minfx = minfx + 0.1*range; minfx = minfx - 0.1*range; plenv(points[X_IX][0], points[X_IX][n-1], minfx, maxfx, 0, 1); plcol0(GREEN); // Select color for labels pllab('x', "f(x)", "Polynomial Function"); // Plot the velocity. plcol0(BLUE); // Color for plotting curve plline(n, points[X_IX], points[X_IX]); plend(); }

/*---------------------------------------------------------- Function: getMin Parameters: array - reference to an array with double values n - number of elements in the array Returns min: the minimum value found in the array Description: Traverses the array to find its minimum value. ----------------------------------------------------------------*/ double getMin(double *array, int n) { int ix; double min = array[0]; for(ix = 1; ix < n; ix = ix +1) if(min > array[ix]) min = array[ix]; return(min); }

/*---------------------------------------------------------- Function: getMax Parameters: array - reference to an array with double values n - number of elements in the array Returns max: the maximum value found in the array Description: Traverses the array to find its maximum value. ----------------------------------------------------------------*/ double getMax(double *array, int n) { int ix; double max = array[0]; for(ix = 1; ix < n; ix = ix +1) if(max < array[ix]) max = array[ix]; return(max); }