Topic L solutions

Solutions TOPIC L: Complete Exercises.

Exercises :

(D1)

(S1)

(S2)

(S3)

(X1)

(H1)

(H2)

(T1)

D1

Exercise

S1

Exercise

Hint: om het te testen vul je de database met enkele records. Dan kan je je procedure testen, door naar bvb de 2e klant met maat L te zoeken!

Test het ook met een onbestaand aantal!

S2

Exercise

Hint: met de volgende code rijdt de robot naar het Oosten tot hij zijn bestemming bereikt heeft of een hindernis voor hem detecteert, dan stopt hij:

VAR detectieStand : DetectieStandAr;
bestemming: BOOLEAN;
BEGIN

StartMotor(WEST);
(* robot begint naar het westen te rijden*)

REPEAT
    bestemming := GeefStandSensors(detectieStand);
      (* rij verder tot 1 van de sensors veranderd *)
UNTIL bestemming OR detectieStand[WEST];
      (* stop als bestemming bereikt of hindernis voor hem, anders doe je verder met de REPEAT *)

StopMotor(WEST):

S3

MODULE S3;
<* NOOPTIMIZE + *> <* WOFF + *>
    FROM IO IMPORT RdChar, WrChar, WrStr, RdStr, WrLn, RdLn, RdCard, WrCard, RdInt, WrInt,RdReal, WrReal, WrFixReal, RdBool, WrBool, RdKey, KeyPressed;
    FROM RealMath IMPORT sqrt, exp, sin, cos, tan, arcsin, arccos, arctan, power, round;
    FROM Lib IMPORT Delay; (* Wait n milliseconds *)
    FROM Windows IMPORT VK_ESCAPE;
    FROM Wimdows IMPORT SetFont, Text, GetKeyPressed, GetTextSize;
    FROM Wimdows IMPORT Window, KillWindow, Line, Ellipse, Disc, Circle, Rectangle, _clrBLACK, _clrBLUE, _clrGREEN, _clrCYAN, _clrRED, _clrMAGENTA, _clrLIGHTRED;
         (* zie C:/Bin/Xds/Def/Ts/Graph.def *)
   (* A. Constants *)
    CONST SCREEN_SIZE = 600;
          NBR = 10;
          SIZE = 4;
        EXITMESSAGE = "Press 'ESC' To Finish Program";

   (* B. Types *)
TYPE PointRc = RECORD
                           x, y: REAL;
      (*4*)
      (*6*)
                       END;

   (* C. Procedures *)
PROCEDURE Square(x0,y0,size,colour:CARDINAL);
BEGIN
    Rectangle (x0 - size/2,y0 - size/2,x0 + size/2,y0 + size/2, colour,TRUE);
END Square;

PROCEDURE Asterisk(x0,y0,size,colour:CARDINAL);
    VAR a:CARDINAL;
BEGIN
    a:= VAL(CARDINAL,((VAL(REAL,size)/(2.0))*0.7071) ); (* cos(45)*)

    Line(x0-size/2, y0, x0+size/2,y0, colour);
    Line(x0, y0+size/2, x0, y0-size/2, colour);
    Line(x0-a, y0+a, x0+a, y0-a, colour);
    Line(x0+a, y0+a, x0-a, y0-a, colour);
END Asterisk;

PROCEDURE CalculateDistance(p1, p2: PointRc): REAL;
BEGIN
    RETURN sqrt((p1.x-p2.x)*(p1.x-p2.x) + (p1.y-p2.y)*(p1.y-p2.y));
END CalculateDistance;

PROCEDURE AverageDistance(p: PointRc; points: ARRAY OF PointRc): REAL;
    VAR sum : REAL;
      i: CARDINAL;
BEGIN
    sum := 0.0;
    FOR i := 0 TO HIGH(points) DO
      sum := sum + CalculateDistance(p, points[i]);
    END;
    RETURN sum / VAL(REAL, HIGH(points) + 1);
END AverageDistance;

(* 2 make procedure PlotArray *)
    (*6 change procedure PlotArray*)

(* 3 procedure to calculate centre of gravity *)

   (* D. Variables*)
     VAR k, w, h :CARDINAL;
       (*1 define arr*)
       (*3 define cg *)
BEGIN
    WrLn;
Window("Topic L Exercise S3",SCREEN_SIZE,SCREEN_SIZE);
(* fill array *)
    arr[1].x := 7.3;   arr[1].y := 8.4E-1;
    arr[2].x := 14.2; arr[2].y := 7.34;
    arr[3].x := 1.4;   arr[3].y := 6.23;
    arr[4].x := 1.0E1; arr[4].y := 1.0E1;
    arr[5].x := 2.5;   arr[5].y := 4.5;
    arr[6].x := 5.2;   arr[6].y := 10.4;
    arr[7].x := 3.4;   arr[7].y := 5.432;
    arr[8].x := 14.6; arr[8].y := 9.8;
    arr[9].x := 12.2; arr[9].y := 15.8;
    arr[10].x := 4.5; arr[10].y := 4.5;

(* plot array *)
    (*2 call plot procedure for arr *)

(* calculate centre of gravity *)
     (*3 call procedure *)

(* plot centre of gravity *)
     (*3 draw asterisk on cg *)

(* distance to cg for every point*)
     (*4 use the given CalculateDistance procedure *)

(*5 *)

(*6 call plot array again*)

(* tell user to press escape to finish the program... *)
SetFont(1, _clrLIGHTRED);
GetTextSize(EXITMESSAGE, 1, w, h);
Text(EXITMESSAGE, SCREEN_SIZE/2 - w/2, SCREEN_SIZE - 10 - h);
(* ...and program will wait here until user presses escape *)
REPEAT
    Delay(25);
UNTIL (GetKeyPressed(k) AND (k = VK_ESCAPE));
(* finally close the window *)
KillWindow();

END S3.

Exercise

Solution

cg.x = 6.8, cg.y = 7.4
distance to cg: arr[1].distance = , arr[2].distance = , arr[3].distance = , ...
average distance to cg = 6.44
Points further away from cg than average:...

Solutions TOPIC L: Complete Exercises.

Contents :

Exercises :

D1

S1

S2

S3

X1

H1

H2

T1