Polar1.bas

 '*********************************************** 
 ' 
 'Polar1.bas by Nally + April 2000 
 'Released as open source 
 ' 
 'Polar1.bas plots the function defined 
 'by R = 2.5 + 2*sin(12*phi) using polar 
 'coordinates. 
 ' 
 'To change the function plotted, locate 
 'the branch label [Plot.click]. The 
 'function is defined a few lines below 
 'that branch label. 
 ' 
 '*********************************************** 
 pi = 3.141592 
 PlotType$ = "Markers" 
 MarkerValue$ = "set" 
 LineValue$ = "reset" 
 Scalefactor = 1 
 BiggestXY = 0 
 xmin = 0 
 xmax = 0 
 ymin = 0 
 ymax = 0 
 Dim R(360) 
 Dim x(360) 
 Dim y(360) 
 Dim xscaled(360) 
 Dim yscaled(360) 
 Dim xplot(360) 
 Dim yplot(360) 
 NoMainWin 
 WindowWidth = 440 
 WindowHeight = 265 
 Graphicbox #main.PlotArea, 214, 21, 200, 200 
 Button #main.Plot, "Plot !", [Plot.click], UL, 25, 126, 170, 30 
 Groupbox #main.groupbox4, "Plot Appearance", 26, 16, 168, 105 
 Radiobutton #main.radioMarkers, " Plot markers", [markers.Set], [markers.Set], 38, 46, 112, 20 
 Radiobutton #main.radioLines, " Plot Lines", [Lines.Set], [Lines.Set], 38, 71, 96, 20 
 Button #main.About, "About...", [About.click], UL, 30, 186, 74, 25 
 Button #main.Quit, "Quit", [Quit.click], UL, 118, 186, 72, 25 
 Open "Plotting Polar Coordinates" For Window As #main 
 Print #main.PlotArea, "fill white; flush" 
 Print #main, "font arial 10" 
 Print #main, "trapclose [Quit.click]" 
 GoSub [Print.Initial.Control.Values] 
 [main.inputLoop] 'wait here for input event 
 Wait 
 GoTo [main.inputLoop] 
 [Quit.click] 
 Close #main: End 
 [Print.Initial.Control.Values] 
 Print #main.radioMarkers, "Set" 
 Print #main.PlotArea, "fill white" 
 Return 
 [markers.Set] 
 Print #main.radioMarkers, "value? MarkerValue$" 
 If (MarkerValue$ = "set") Then 
 PlotType$ = "Markers" 
 End If 
 If (MarkerValue$ = "reset") Then 
 PlotType$ = "Lines" 
 End If 
 GoTo [main.inputLoop] 
 [Lines.Set] 
 Print #main.radioLines, "value? LineValue$" 
 If (LineValue$ = "set") Then 
 PlotType$ = "Lines" 
 End If 
 If (LineValue$ = "reset") Then 
 PlotType$ = "Markers" 
 End If 
 GoTo [main.inputLoop] 
 [Plot.click] 
 'for all angles between zero and 360 degrees, 
 'find the value of R as defined by 
 'R = 2.5 + 2*sin(12*phi) 
 For degree = 0 to 360 
 phi = (degree/360) *(2*pi) 
 R(degree) = 2.5 + 2*Sin(12*phi) 
 Next degree 
 'Convert polar coordinates to 
 'cartesian coordinates 
 For degree = 0 to 360 
 phi = (degree/360) * (2*pi) 
 x(degree) = R(degree) * Cos(phi) 
 y(degree) = R(degree) * Sin(phi) 
 Next degree 
 'Find the extreme values of all cartesian 
 'x and y values as a prelude to 
 'finding the scalefactor 
 xmax = 0 
 xmin = 0 
 ymax = 0 
 ymin = 0 
 For degree = 0 to 360 
 If (x(degree) > xmax) Then xmax = x(degree) 
 If (x(degree) < xmin) Then xmin = x(degree) 
 If (y(degree) > ymax) Then ymax = y(degree) 
 If (y(degree) < ymin) Then ymin = y(degree) 
 Next degree 
 BiggestXY = 0 
 If (abs(xmax) > BiggestXY) Then BiggestXY = abs(xmax) 
 If (abs(xmin) > BiggestXY) Then BiggestXY = abs(xmin) 
 If (abs(ymax) > BiggestXY) Then BiggestXY = abs(ymax) 
 If (abs(ymin) > BiggestXY) Then BiggestXY = abs(ymin) 
 'Establish the scalefactor 
 Scalefactor = 90 / BiggestXY 
 'Create a scaled set of the cartesian coordinates 
 'so that the data will plot nicely in the Graphicbox 
 For degree = 0 to 360 
 xscaled(degree) = Scalefactor * x(degree) 
 yscaled(degree) = Scalefactor * y(degree) 
 Next degree 
 'Shift the data set to the center of the 
 'Graphicbox, while also reversing the 
 'direction of y. 
 For degree = 0 to 360 
 xplot(degree) = 100 + xscaled(degree) 
 yplot(degree) = 100 - yscaled(degree) 
 Next degree 
 If (PlotType$ = "Lines") Then [Skip.To.Lines] 
 'If markers have been selected, plot markers 
 Print #main.PlotArea, "discard" 
 Print #main.PlotArea, "cls" 
 Print #main.PlotArea, "fill white" 
 Print #main.PlotArea, "down" 
 For degree = 0 to 360 
 Print #main.PlotArea, "place " + Str$(xplot(degree)) + " " + Str$(yplot(degree)) 
 Print #main.PlotArea, "circle 2" 
 Next degree 
 GoTo [Plotting.Accomplished] 
 [Skip.To.Lines] 
 'If lines have been selected, plot lines 
 Print #main.PlotArea, "discard" 
 Print #main.PlotArea, "cls" 
 Print #main.PlotArea, "fill white" 
 Print #main.PlotArea, "down" 
 For degree = 1 to 360 
 xplot1 = xplot(degree - 1) 
 yplot1 = yplot(degree - 1) 
 xplot2 = xplot(degree) 
 yplot2 = yplot(degree) 
 Print #main.PlotArea, "line " + Str$(xplot1) + " " + Str$(yplot1) + " " + _ 
 Str$(xplot2) + " " + Str$(yplot2) 
 Next degree 
 [Plotting.Accomplished] 
 Print #main.PlotArea, "flush" 
 GoTo [main.inputLoop] 
 [About.click] 
 Notice "About Plotting Polar Coordinates" + Chr$(13) + _ 
 "By Nally + April 2000 " + Chr$(13) + _ 
 "Made with Liberty Basic " + Chr$(13) + _ 
 "Released as open source " 
 GoTo [main.inputLoop]