scrsho.txt

《Delphi常用数值算法集》的配书源码

Procedure SCRSHO;
const
    s1 = '%10.6f';  s2 = '%4.1f';
var
    ISCR,JSCR,I,J,JZ:integer;  X,X1,X2,DX,YBIG,YSML,DYJ:real;
    Y:array[0..60] of real;
    SCR:array of array of string;
    BLANK,ZERO,YY,XX,FF,STR1,STR2:string;
begin
    SetLength(SCR,61,22);
    ISCR:=60;
    JSCR:=21;
    BLANK:=' ';
    ZERO:='-';
    YY:='1';
    XX:='-';
    FF:='x';
    //Enter X1,X2 (X1=X2 to stop)
    X1:=-5; 
    X2:=5; 
    If X1 = X2 Then Exit ;
    For J:=1 To JSCR do
    begin
        SCR[1, J]:=YY;
        SCR[ISCR, J]:=YY;
    end;
    For I:=2 To ISCR - 1 do
    begin
        SCR[I, 1]:=XX;
        SCR[I, JSCR]:=XX;
        For J:=2 To JSCR - 1 do
            SCR[I, J]:=BLANK;
    end;
    DX:=(X2 - X1) / (ISCR - 1);
    X:=X1;
    YBIG:=0 ;
    YSML:=YBIG;
    For I:=1 To ISCR do
    begin
        Y[I]:=FUNC(X);
        If Y[I] < YSML Then YSML:=Y[I];
        If Y[I] > YBIG Then YBIG:=Y[I];
        X:=X + DX;
    end; 
    If YBIG = YSML Then YBIG:=YSML + 1 ;
    DYJ:=(JSCR - 1) / (YBIG - YSML);
    JZ:=1 - Round(YSML * DYJ);
    For I:=1 To ISCR do
    begin
        SCR[I, JZ]:=ZERO;
        J:=1 + Round((Y[I] - YSML) * DYJ);
        SCR[I, J]:=FF;
    End;
    STR1:=' ';
    For I:=1 To ISCR do
        STR1:= STR1+SCR[I, JSCR];
    Writeln(F,Format(s1,[YBIG]),' ',STR1);
    For J:=JSCR - 1 DownTo 2 do
    begin
        STR2:=' ';
        For I:=1 To ISCR do
            STR2:= STR2+SCR[I, J];
        Writeln(F,'           ',STR2);
        //Writeln(F);
    End;
    STR1:=' ';
    For I:=1 To ISCR do
        STR1:= STR1+SCR[I, 1];
    Writeln(F,Format(s1,[YSML]),' ',STR1);
    Writeln(F,'            ',Format(s2,[X1]),
    '                                                    ',Format(s2,[X2]));
end;