F # Draws a heart line in a PictureBox in a form

Heart Line equation: R=a (1-sinθ)

Convert to parametric equation

X=2R (sin (t)-sin (2t)/2)

y=2r (cos (t)-cos (2t)/2)

Program code:

  Learn more about  F#  on  http://fsharp.net //  See the f#  Tutorial project for more help. DLL if not, you need to add the reference manually Open system.drawingopen system.windows.forms[<entrypoint>]let main  argv =     system.console.writeline ("Heart Line Drawing Program  by tsybius")      system.console.writeline ("September 21, 2014  21:53:52")      System.Console.WriteLine ("=============================\n")     system.console.writeline (" Building Forms (Form)     //add form Form    let frmheart = new  form ()         //set form Properties     frmheart.name  <-  "Frmheart"     frmHeart.Text <-  "Heart Line  r=a (1-sinθ)"      frmheart.autoscaledimensions <- new system.drawing.sizef (6.0f, 12.0f)     frmheart.autoscalemode <-&nBsp system.windows.forms.autoscalemode.font    frmheart.clientsize <- new  System.Drawing.Size (480, 458)     frmHeart.FormBorderStyle <-  system.windows.forms.formborderstyle.fixed3d    frmheart.startposition <-  system.windows.forms.formstartposition.centerscreen    //frmheart.backcolor <-  System.Drawing.SystemColors.ActiveCaption    frmHeart.MaximizeBox <-  false    frmheart.minimizebox <- false     frmheart.showicon <- false    frmheart.topmost <- true         system.console.writeline ("Building picture Frame (PictureBox)")      //set up picture frame picturebox    let picimage = new  System.Windows.Forms.PictureBox ()         picimage.dock <- system.windows.forms.dockstyle.fill     Picimage.location <- new system.drawing.point (0, 0)      picimage.name <-  "Picimage"     picImage.Size <- new  System.Drawing.Size (480, 458)     picImage.BackColor <-  system.drawing.systemcolors.activecaption    picimage.image <- new  Bitmap (picimage.width, picimage.height)     frmheart.controls.add (picImage)          system.console.writeline ("Start drawing image")     //drawing image     let grph: graphics = graphics.fromimage (picImage.Image)          system.console.writeline ("Draw horizontal axis")     //Horizontal axis      grph. DrawLine ((New pen (brushes.green, 5.0f)),  30,  135, 450, 135)      grph. FillPolygon (brushes.green, //left arrow          [| new  Point (60, 125);             new point (10,  135);             new point (60, 145 );             new point (90, 135)  |]);     grph. FillPolygon (brushes.green, //right ARROW         [| new point ( 420, 125);             new point (470,  135);             new point (420,  145);             new point (390, 135)  |]);     &Nbsp;          system.console.writeline ("Draw vertical axis")      //longitudinal axis     grph. DrawLine ((New pen (brushes.green, 5.0f)),  240, 30, 240, 428)       grph. FillPolygon (brushes.green, //on the side arrow          [| new  Point (240,&NBSP;20);            new point (225, &NBSP;30);             new point (240, 70) ;             new point (255, 30)  |]);     grph. FillPolygon (brushes.green, //lower side Arrow          [| new  Point (240, 370);            new point (225,  400);      &nBsp;      new point (240, 445);             new point (255, 400)  |]);                 System.Console.WriteLine ("Draw Heart Line")     //Heart Draw begins     let r =  50.0    let funt  (T: int)  =  (float) t * 2.0 *  3.1416 / 10000.0 : float    //Horizontal     let  funx  (t: float)  =         -1 *  ( int) (2.0 * r *  (sin (t)  - sin (2.0 * t)  / 2.0 + 0.5) )  : int    //ordinate     let funy  (t: float)   =         -1 *  (int) (2.0 * r *  (cos (t)  - cos (2.0&NBSP;*&NBSP;T)  / 2.0 + 0.5))  :  int    let p: Point[] =        &NBSP;&NBSP;[|&NBSP;FOR&NBSP;T&NBSP;IN&NBSP;0&NBSP, ....  10000 ->             new  Point (Funx (Funt (t))  + 290, funy (Funt (t))  + 235)  |]     grph. FillPolygon (brushes.pink, p)     grph. DrawPolygon ((New pen (brushes.red, 5.0f)),  p)         // Heart Draw End         system.console.writeline ("draw character")      Let brushstr1 = new solidbrush (Color.Blue)     let fontstr1 =  new font ("Consolas",  24.0f)     grph. DrawString ("cardioid",  fontstr1, brushstr1, 160.0f, 175.0f )     grph. DrawString ("R=a (1-sinθ)", fontstr1, brushstr1, 140.0f, 215.0f )          system.console.writeline ("Draw signature: Tsybius")     let  Brushstr2 = new solidbrush (Color.White)     let fontstr2 =  New font ("Consolas",  24.0f)     grph. DrawString ("TSYBIUS&NBSP;2014/9/21", fontstr2, brushstr2, 150.0f, 405.0f )          system.console.writeline (open form)     //open the form      let result = frmheart.showdialog ()          system.console.writeline ()     //Press any key to continue (exit)      System.Console.WriteLine ("Press any key to continue")     let temp = system.console.readkey ()     let&nBsp;temp = system.console.write ("\b\t")  //Delete the pressed "any key" character     0 //  Returns an integer exit code

To run the example:

END

F # Draws a heart line in a PictureBox in a form