MuPAD Code

  q := abs(Im(exp(x+I*y))):

  conts := 21:
  projectionlevel:=-10:
  ylimit := 2*PI:
  xlimit := 3:
  submeshlevel := 5:

zmin := -10:
zmax := 10:
color := zip(RGB::SapGreen, RGB::LightBlue,
             (a, b) -> (q(x,y)-zmin)/(zmax-zmin)*a
                      +(zmax-q(x,y))/(zmax-zmin)*b):

funcplot := plot::Function3d(q(x,y),
                             x = -xlimit..xlimit,
                             y = -ylimit..ylimit,
                             Mesh = [23, 23],
                             Submesh = [submeshlevel,submeshlevel],
                             LineColor = RGB::Black.[0.4],
                             LineWidth = 0.15,
                             FillColorFunction = color,
                             AxesTitleFont = ["Courier New", Bold, 14],
                             ViewingBoxZRange = -10..10,
                             YTicksNumber = None,
                             YTicksAt = [-3*PI/2 = "-3 PI/2", -PI = "-PI", -PI/2 = "-PI/2", -2*PI = "-2 PI",
                                         0 = "0", 
                                         PI/2 = "PI/2", PI = "PI",  3*PI/2 = "3 PI/2", 2*PI = "2 PI"]
                            ):

contours := plot::modify(funcplot,
                         ZContours = [Automatic, conts],
                         LineWidth = 0.2,
                         LineColor = RGB::Gray90.[0.5],
                         XLinesVisible = FALSE,
                         YLinesVisible = FALSE,
                         Filled = FALSE
                        ):
                        
projcontours := plot::Transform3d([0, 0, projectionlevel],
                                  [1, 0, 0, 0, 1, 0, 0, 0, 0], 
                                   plot::modify(funcplot, ZContours = [Automatic, conts],
                                                LineWidth = 0.2,
                                                LineColorType = Dichromatic,
                                                LineColor = RGB::DarkGreen.[0.99],
                                                LineColor2 = RGB::Yellow.[0.99],
                                                XLinesVisible = FALSE,
                                                YLinesVisible = FALSE,
                                                Filled = FALSE
                                               )
                                  ):
                             
camera := plot::Camera([25, 80, 120],
                       [0.5, 1, 0],
                       0.15
                      ):
                             
ploteverything := plot::Canvas(funcplot, contours, projcontours,
                               Width = 8.5*unit::inch, 
                               Height = 7*unit::inch,
                               camera
                              ): 
                          
plot(ploteverything)