MathGroup Archive 1992

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

Search the Archive

Problems plotting arrays

  • To: mathgroup at
  • Subject: Problems plotting arrays
  • From: dmwood at (David M. Wood)
  • Date: Wed, 28 Oct 92 11:20:29 MST

I've noticed what appear to be two bugs in Mma 2.1, the 
first involving contouring and the second in the new 
package ListShadowPlot, when plotting arrays.  I'm using a NeXT.

**BUG(?) #1**
In a Notebook I wrote for Mma 2.0, I read in external data
from a file MyDat. The data was written into this file as 
numbers ((a(i,j),j=1,numx),i=1,numy), and read into Mathematica via

NumX=Read[MyDat, Number]  <= Number of elements in row
NumY=Read[MyDat, Number]  <= Number of elements in column
a=ReadList[MyDat, Table[Real] ]; <= Read in the array as a
                                    flat sequence of numbers
b=Partition[a,NumX]; <= Break it logically into rows

Under Mma 2.1, , e.g., for  36 rows and 26 columns in the
array b, surface plots like

ListPlot3D[b, ...directives]

continue to work fine.  However, an attempt to use the 
*new* package ListShadowPlot3D [in Graphics`Graphics3d`] 
to plot the same data, via


yields (for the same 36 row by 26 column array b above)

Part::partw: Part 27 of {<<26>>} does not exist.
Part::partw: Part 27. of {<<26>>} does not exist.
Part::partw: Part 27 of {<<26>>} does not exist.
   Further output of Part::partw
     will be suppressed during this calculation.
Then generally the swap file begins to grow....The
object b looks precisely as it should.

**BUG(?) #2**
The thickness directives in

ContourStyle->{{Thickness[.002]}, {Thickness[.002]},
 {Thickness[.002]}, {Thickness[.002]}, {Thickness[.006]}},

which under Mma 2.0  made every fifth contour 3 times as thick, 
no longer work, giving the error message

   -- Message text not found -- (
    {{Thickness[0.002]}, <<3>>, {Thickness[0.006]}})
and all contours come out the same thickness.  [But boy! -Is 
the contouring faster than it was under Mma 2.0!]  Apart from this, 
the contour plots are correct.

Can anyone confirm these problems and/or suggest workarounds?

  • Prev by Date: changing the font of "input"
  • Next by Date: Re: Elliptic integral problems in mma
  • Previous by thread: changing the font of "input"
  • Next by thread: Mma on RISC