Thread: please help me

Before High resolution graphic displays became common, computer terminals were often used to display graphs of equations using only text characters. A typical
technique was to create a vertical graph by spacing over on the screen, then displaying an *. Write a program that displays the graph of an increasing frequency sine wave this way. The program should ask the user for an initial step-size in degrees and the number of lines of the graph to display.

that was my assignment, and i'm almost done, but i got serveral error messages and i don't know how to fix my program, please help me

/* This program wlil graph an increasing frequency sine wave */

#include <stdio.h> /* printf, scanf definitions */
#include <math.h> /* math definitions */
#define pi 3.14159

int
main(void)
{
double stepsize; /* input - stepsize */
double first_value; /* input - first value */
double number_of_lines; /* input - number of lines */
double output;
double loop;
double scale;
double increment;
double y;
double sin;

/* Get the step size, first value, and number of lines */
printf("Enter the inial step size> ");
scanf("%d", &stepsize);
printf("Enter the first value> ");
scanf("%d", &first_value);
printf("Enter the number of lines> ");
scanf("%d", &number_of_lines);

for (int i = 0; i<number_of_lines; ++i)
{
double y = sin(exp(first__value + i * stepsize * 2 * pi / 180));
y *= 10.0; /* Scaling */
y += 5.0; /* Scaling */

/* Output y spaces by using loop */
for (int j = 0; j < y; ++j)
{
printf(" ");
}
printf("*\n"); /* Output '*' and new line) */
}
return 0;
}

typo with this variable

Code:

double y = sin(exp(first__value + i * stepsize * 2 * pi / 180));

look at what you are passing to sin()

Code:

double y = sin(exp(first_value + i * stepsize * 2 * pi / 180));

Code:

/* This program wlil graph an increasing frequency sine wave */
        
#include <stdio.h>                      /* printf, scanf definitions */
#include <math.h>                       /* math definitions          */
#define pi 3.14159
        
int
main(void)
{
        double stepsize;                /* input - stepsize     */
        double first_value;             /* input - first value  */
        double number_of_lines;         /* input - number of lines */
        double output;
        double loop;
        double scale;
        double increment;
        double y;   
        double sin;
        
        /* Get the step size, first value,  and number of lines */
        printf("Enter the inial step size> ");
        scanf("%d", &stepsize);
        printf("Enter the first value> ");
        scanf("%d", &first_value);
        printf("Enter the number of lines> ");
        scanf("%d", &number_of_lines);

        for (int i = 0; i<number_of_lines; ++i)
{
        double y = sin(exp(first_value + i * stepsize * 2 * pi / 180));
        y *= 10.0; /* Scaling */
        y += 5.0;  /* Scaling */

        /* Output y spaces by using loop */
        for (int j = 0; j < y; ++j)
{
        printf(" ");
}
        printf("*\n"); /* Output '*' and new line) */
}
        return 0;
}

code tags added by Kermi3

i'm still getting these error messages...

sine.c: In function `main':
sine.c:28: error: `for' loop initial declaration used outside C99 mode
sine.c:30: error: called object is not a function
sine.c:35: error: `for' loop initial declaration used outside C99 mode[SIZE=5]

Code:

/* This program wlil graph an increasing frequency sine wave */

#include <stdio.h>                      /* printf, scanf definitions */
#include <math.h>                       /* math definitions          */
#define pi 3.14159

int
main(void)
{
        double stepsize;                /* input - stepsize     */
        double first_value;             /* input - first value  */
        double number_of_lines;         /* input - number of lines */
        double output;
        double loop;
        double scale;
        double increment;
        double y;
        double sin;

        /* Get the step size, first value,  and number of lines */
        printf("Enter the inial step size> ");
        scanf("%d", &stepsize);
        printf("Enter the first value> ");
        scanf("%d", &first_value);
        printf("Enter the number of lines> ");
        scanf("%d", &number_of_lines);

        for (int i = 0; i<number_of_lines; ++i)
{
        double y = sin(exp(first__value + i * stepsize * 2 * pi / 180));
        y *= 10.0; /* Scaling */
        y += 5.0;  /* Scaling */

        /* Output y spaces by using loop */
        for (int j = 0; j < y; ++j)
{
        printf(" ");
}
        printf("*\n"); /* Output '*' and new line) */
}
        return 0;
}

I havent changed a thing. just used the code thingy to make it look nicer for others

oh...i didn't know what salem was talking about...thanks...please help me with my errors

Code:

/* This program wlil graph an increasing frequency sine wave */

#include <stdio.h>                      /* printf, scanf definitions */
#include <math.h>                       /* math definitions          */
#define pi 3.14159

int
main(void)
{
        double stepsize;                /* input - stepsize     */
        double first_value;             /* input - first value  */
        double number_of_lines;         /* input - number of lines */
        double output;
        double loop;
        double scale;
        double increment;
        double y;
        double sin;

        /* Get the step size, first value,  and number of lines */
        printf("Enter the inial step size> ");
        scanf("%d", &stepsize);
        printf("Enter the first value> ");
        scanf("%d", &first_value);
        printf("Enter the number of lines> ");
        scanf("%d", &number_of_lines);

        for (int i = 0; i<number_of_lines; ++i)
{
        double y = sin;
        (exp(first_value + i * stepsize * 2 * pi / 180));
        y *= 10.0; /* Scaling */
        y += 5.0;  /* Scaling */

        /* Output y spaces by using loop */
        for (int j = 0; j < y; ++j)
{
        printf(" ");
}
        printf("*\n"); /* Output '*' and new line) */
}
        return 0;
}

and these are the only errors i have left, please help me fix it...i don't know how

sine.c:28: error: `for' loop initial declaration used outside C99 mode
sine.c:36: error: `for' loop initial declaration used outside C99 mode

ahhh! the program is supposed to draw an increasing frequency sine function, but all i get is "*"

Code:

/* This program wlil graph an increasing frequency sine wave */

#include <stdio.h>                      /* printf, scanf definitions */
#include <math.h>                       /* math definitions          */
#define pi 3.14159
 
int
main(void)
{
        double stepsize;                /* input - stepsize     */
        double first_value;             /* input - first value  */
        double number_of_lines;         /* input - number of lines */
        double output;   
        double loop;
        double scale;
        double increment;
        double y;
        double sin;
        double i;
        double j;
        /* Get the step size, first value,  and number of lines */
        printf("Enter the inial step size> ");
        scanf("%d", &stepsize);
        printf("Enter the first value> ");
        scanf("%d", &first_value);
        printf("Enter the number of lines> ");
        scanf("%d", &number_of_lines);
        
        for (i=0; i<number_of_lines; ++i) //
{
        double y = sin;
        (exp(first_value + i * stepsize * 2 * pi / 180));
        y *= 10.0; /* Scaling */
        y += 5.0;  /* Scaling */
 
        /* Output y spaces by using loop */
        for (j=0; j < y; ++j) //
{
        printf(" ");
}
        printf("*\n"); /* Output '*' and new line) */
}
        return 0;
}

my compiler doesn't say any of those errors

Originally Posted by my_username1234

my compiler doesn't say any of those errors

try "gcc -Wall -ansi filename.c"
to display all warnings

EDIT: i.e if you are using UNIX