MathGroup Archive 2000

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Hatching instead of a colour?

  • To: mathgroup at
  • Subject: [mg21469] Re: Hatching instead of a colour?
  • From: "Mariusz Jankowski" <mjkcc at>
  • Date: Tue, 11 Jan 2000 04:17:49 -0500 (EST)
  • Organization: University of Maine System/MSLN
  • References: <85cmc0$>
  • Sender: owner-wri-mathgroup at

Harald, try the following:

plot your original data

plota = ListDensityPlot[  your data , options];

find the location of all the zeros, for example use

zeros=Position[your data, 0]

Next generate a 2D Graphics object showing all of these positions, for
example, here I map all the x,y coordinate pairs returned by Position to the
graphics primitive Point (this is the easiest, but you may want to use
Rectangle). Note that you should use Reverse, since the coordinate ordering
in a matrix and 2D Graphic are reversed!

gr = Graphics[{PointSize[0.02], RGBColor[1,0,0], Point /@ Reverse /@ zeros}]

Finally, combine the graphics:

Show[plota, gr]

Good luck, Mariusz

Harald Giese <giese at> wrote in message
news:85cmc0$lfs at
> Hi all!
> There is a matrix of values spanning from negative to positive values
> and a second one indicating, which of the first matrix' elements are
> missing values, i.e. whether the "0" is a value or just meas "nil".
> ListDensityPlot plots a nice gray scale graphic, but I need to indicate
> the missing entries in that plot. I thought about replacing the colour
> of these "empty" elements by a pattern or hatching. Has someone an idea
> how to do that with Mathematica?
> Thank you in advance,
> Harald
> --- This message was entirely written using recycled electrons ---
> Harald Giese
> Email: giese at
> Phone: +49 (0)40 42838 5796; Fax: +49 (0)40 5605724
> Institut fuer Meereskunde der Universitaet Hamburg
> (Institute of Oceanography of the University of Hamburg)
> Troplowitzstrasse 7, D-22529 Hamburg

  • Prev by Date: Re: How do I copy cells to my e-mail browser for submissions...
  • Next by Date: Re: Diophantine Equations
  • Previous by thread: Re: Hatching instead of a colour?
  • Next by thread: Re: Inner product can be modified?