. 9.2.
. 9.2
, , :
...
//---------------------------------------------------------------------------
double a,b,h,y_min,y_max;
int n;
typedef double (*Tfun)(double);
Tfun f;
double fun0(double);
double fun1(double);
double fun2(double);
//----------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
Edit1->Text="-3,1416"; // a
Edit2->Text="3,1416"; // b
Edit3->Text="50"; // n
RadioGroup1->ItemIndex = 0;
}
//----------------- ------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
double x, r;
a=StrToFloat(Edit1->Text);
b=StrToFloat(Edit2->Text);
n=StrToInt(Edit3->Text);
h = (b-a)/n;
switch(RadioGroup1->ItemIndex) {
case 0: f = fun0; break;
case 1: f = fun1; break;
case 2: f = fun2; break;
}
y_min = y_max = f(a);
for (x = a+h; x<=b; x+=h) {
r = f(x);
if(y_min>r)
y_min = r;
if(y_max<r)
y_max = r;
}
}
//------------------------ Chart ----------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
Chart1->Series[0]->Clear(); //
for(double x=a; x<=b; x+=h)
Chart1->Series[0]->AddXY(x,f(x));
}
//--------------------- ----------------------------------------
void __fastcall TForm1::Button3Click(TObject *Sender)
{
Chart1->CopyToClipboardMetafile(True);
}
//--------------------- Image ---------------------------
void __fastcall TForm1::Button4Click(TObject *Sender)
{
int xmax, ymax, xt, yt, y0, x0;
double hx,hy,x;
Image1->Canvas->Pen->Color=clBlack; //
// Image
xmax = Image1->Width;
ymax = Image1->Height;
// Image
Image1->Canvas->Rectangle(0,0,xmax,ymax);
//
y0=ymax/2;
x0=xmax/2;
//
Image1->Canvas->MoveTo(0,y0);
Image1->Canvas->LineTo(xmax,y0);
Image1->Canvas->MoveTo(x0,0);
Image1->Canvas->LineTo(x0,ymax);
Image1->Canvas->Pen->Color=clRed; //
Image1->Canvas->Pen->Width=2; //
//
hx=(b-a)/xmax;
hy=(y_max-y_min)/ymax;
Image1->Canvas->MoveTo(ceil(x0+a/hx),ceil(y0-f(a)/hy));
for(x=a; x<=b; x+=h)
Image1->Canvas->LineTo(ceil(x0+x/hx),ceil(y0-f(x)/hy));
}
//------------------------------------------------------------
double fun0(double r)
{
return sin(r);
}
//------------------------------------------------------------
double fun1(double r)
{
return r*r;
}
//------------------------------------------------------------
double fun2(double r)
{
return r*r*r;
}