Question

怎样用c语言画函数曲线图

1.怎样用c语言画关于y=f(x)在某一x取值范围内曲线图呢(应是平滑曲线吧).
2.在Turbo C for Windows 3.0中画图(正确调用了graphics.h文件)对程序编译成功但却提示比如:未定义符号:'_putpixel'之类的东西...
然后运行时会弹出一框写:NTVDM CPU遇到无效的指令.最后程序运行不成功.为什么呢?
请C高手帮忙.

Answer 1

/*请不要看完了就走人*/
/*帮帮忙,采纳我的答案!*/
#include<stdio.h>
#include<math.h>
main(){
double
y;
int
x,m,i;
printf("y=sin(x)
[0<x<2*pi]\n");
for(y=1;y>=-1;y-=0.1){
if(y>=0){
m=asin(y)*10;
for(x=1;x<m;x++)printf("
");
printf("*",m);
for(;x<31-m;x++)printf("
");
printf("*\n");}
else{
m=-1*asin(y)*10;
for(i=0;i<32;i++)printf("
");
for(x=1;x<m;x++)printf("
");
printf("*",m);
for(;x<31-m;x++)printf("
");
printf("*\n",m);
}
}
}

Answer 2

差不多就是这样的:
#include<stdio.h>
#include<graphics.h>
void init();
void draw_xy();
main()
{
float i;
init();
draw_xy();
for(i=-10;i<10.0;i=i+0.01)
putpixel(175+i,200-i*i,RED);
getch();

}
void init()
{
int gd=DETECT,gm;
initgraph(&gd,&gm,"");
cleardevice();
}
void draw_xy()
{
setcolor(RED);
line(50,200,300,200);
outtextxy(300,198,">");
line(175,50,175,400);
outtextxy(172,49,"\136");}

[em01][em01]

Answer 3

DOS里面可以直接操作显存，windows里就不行了，尤其是NT系统。建议用GDI获DX吧