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Question: Why are the level curves wrong when axis mode is switched to log?

Question:Why are the level curves wrong when axis mode is switched to log?

mmcdara 6149 Maple 2015
axis plot3d contour plotting
September 16 2022
1


Using plot3d(..., style=surfacecontour, ...) or contourplot3d(...) displays wrong level curves when some axis are switched to a log mode.

Example:

> 

restart:
> 

interface(version)

`Standard Worksheet Interface, Maple 2015.2, Mac OS X, December 21 2015 Build ID 1097895`

 (1)
> 

X := (0.4000000000e-4*(-R+80.00))/(R*(0.4e-1+M__a)):
> 

plot3d(X, R=0..10, M__a=10^0..10^4, style=surfacecontour, color=gold)

 
> 

plot3d(X, R=0..10, M__a=10^0..10^4, axis[2]=[mode=log], axis[3]=[mode=log], style=surfacecontour, color=gold)

 
> 

plots:-display(
  plots:-contourplot3d(X, R=0..10, M__a=10^0..10^4, axis[2]=[mode=log], axis[3]=[mode=log], color=red),
  plot3d(X, R=0..10, M__a=10^0..10^4, style=surface, color=gold)
)

 
> 

 

Download WrongLevelCurves.mw

 

The problem is not dramatic because there is a workaround.
 

> 

restart:
> 

interface(version)

`Standard Worksheet Interface, Maple 2015.2, Mac OS X, December 21 2015 Build ID 1097895`

 (1)
> 

X := (0.4000000000e-4*(-R+80.00))/(R*(0.4e-1+M__a)):
> 

fig := plot3d(X, R=0..10, M__a=10^0..10^4, style=surfacecontour, color=gold):
Tr  := plottools:-transform((x, y, z) -> [x, log[10](y), log[10](z)]):
plots:-display(Tr(fig), axis[2]=[tickmarks=[seq(i=10^i, i=0..4)]], axis[3]=[tickmarks=[seq(i=nprintf("%1.0e", 10.^i), i=-7..-1)]])

 
> 

 

Download WrongLevelCurves_Workaround.mw

 
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