nm

12238 Reputation

20 Badges

13 years, 257 days

MaplePrimes Activity


These are questions asked by nm

When I use something like plots[display](Array([p1,p2]));  And the plots p1,p2 have been resized before to be small, there is lots of wasted empty space in the final result. I have to manually adjust the size of each Array entry with the mouse to make the fit better. But this solution is not practical. 

Is there an option to do this automatically? Here is an example

restart;

p1:=plot(sin(x), x=-Pi..Pi, size=[300,300]):
p2:=plot(cos(x), x=-Pi..Pi, size=[300,300]):
plots[display](Array([p1,p2]));   #one option
plots[display](Vector[row]([p1,p2])); #another option

Manually, using the mouse, I can, after some adjustments and trrial and errors, get the final result such that the wasted space is removed.

I am asking, becuase if I want to save/export the above final plot as PDF to include in a Latex document, it will look bad with that wasted space there.

How to do this adjustment using code?

In Mathematica for example, this is done using Grid and the Spacing option. I could not find something similar in Maple but I could have overlooked it.

Maple's plot3d makes nice plots, but it is not quite polished enough I feel.

When I compared the same plot with what I get with Mathematica, I found these 3 issues shown below. I am not too good in Maple, so I am not able to see how to improve on this any more.

 

 

The Maple code is

restart;
f:=-x^4-2*y^4+14*x^2*y^2/5:
plot3d(f, x=-5..5,y=-5..5,
   axes     = boxed,
   axesfont = [Times,default,10],
   axis[1]  = [tickmarks=[3,subticks=5]],
   axis[2]  = [tickmarks=[3,subticks=5]],
   axis[3]  = [tickmarks=[3,subticks=5]],
   labeldirections = [horizontal, horizontal, horizontal],	
   labels   = ['x', 'y', 'z'],
   scaling  = unconstrained) 

Compare to Mathematica's output

 

f = -x^4 + (14*x^2*y^2)/5 - 2*y^4; 
Plot3D[f, {x, -5, 5}, {y, -5, 5}, 
 AxesLabel -> {"x", "y", "z"}, 
 PlotRange -> All, 
 BoxRatios -> {1, 1, 1}, ImageSize -> 400]

Another major limitation in Maple's plot3d, is that it does not support `BoxRatios` like option. I asked about this years ago and got help on it, but nothing very satisfactory to use in geneal.

https://www.mapleprimes.com/questions/217092-How-To-Change-box-Ratio-Or-3D-Aspect

I hope Maplesoft can improve on this in next version.

Any suggestion how to improve the above 3 issues for now? The ticks issues for me seems the most annoying, becuase they keep moving around as I rotate the 3d plot.

 

Maple 2020 on windows 10

 

Not that I care about the virtual rating numbers here, but I am wondering why would one suddenly lose 15 point after posting a problem they found in Maple? Is this typical?

https://www.mapleprimes.com/questions/229443-Why-These-ODEs-Hang-Or-Return-Unsolved

3 hrs ago, I was 3001  and when I came to check on the status if any, now it says 2986.

Just wondering why, that is all. Again, this really does not bother me at all as I do not care about these virtual cloud credit points, and I only post here on occasions and when I found some problem. I just like to know why this happened just now, that is all. 

 

 

 

 

 

When I tried these ODE's in Maple 2019, and Maple 2018, they are worked (i.e. gave solutions). Now these ODE's either hang in 2020 or return unsolved. What could have caused this? On Maple 2020, under windows 10:

restart;
ode:=(x^2-1)*diff(y(x),x)^2-y(x)^2+1=0:
dsolve(ode); #hangs

restart;
ode:=(2*x^2+1)*diff(y(x),x)^2+(y(x)^2+2*x*y(x)+x^2+2)*diff(y(x),x)+2*y(x)^2+1=0:
dsolve(ode); # return unsolved

restart;
ode:=x*y(x)^2*diff(y(x),x)^3-y(x)^3*diff(y(x),x)^2+x*(x^2+1)*diff(y(x),x)-x^2*y(x):
dsolve(ode); # return unsolved

restart;
ode:=(diff(y(x),x) = (-y(x)^2+4*a*x)^3/(-y(x)^2+4*a*x-1)/y(x)):
dsolve(ode); #hangs

I noticed that in Maple 2019.2 this problem is also there. But not in Maple 2019.  So something changed from after Maple 2019.

Here is worksheet on Maple 2018 that shows these worked there. But no longer work on Maple 2020. There might be more like these but these the ones I found so far.




issue.mw

Why 

evalf(evalf(''Pi''))

Produces 

But

evalf(''Pi''):
evalf(%)

Produces

      3.141592654

 

 

First 146 147 148 149 150 151 152 Last Page 148 of 217