Tanvas, , , Image, PaintBox, ( GDI Windows) . . . , Y .
Image Additional, PaintBox System.
Canvas:
Pen ( ),
Brush ( ),
Font ( ).
Canvas:
Ellipse ( 1, 1, 2, 2) ( 1, 1), ( 2, 2) ;
MoveTo (, y) (, y);
LineTo (, y) (, y);
Rectangle ( 1, 1, 2, 2) ( 1, 1), ( 2, 2). FrameRect Polyline;
Polygon (const TPoint* Points, const int Points_Size) , ints Points_Size. . Polyline.
TextOut (, , const AnsiString Text) t , , , (, ).
hart Image.
. 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-> //
//
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;
}
( 3) Y (x) S (x) x, a b h ( ) hart Y (x) Image.
1