## 5085 Reputation

11 years, 320 days

## re orient positive terms to the front...

Mainly just symantics, Maple often shifts -'ve terms to the front, how to re-orient terms so the positive terms are always first?

a:= (a2b1-a1b2)*j1+(a4b4-a3b5)*j2

( - a1b2 + a2b1) * j1 + ( - a3b5 + a4b4) * j2

## Is this a bug for a function?...

Maple 2019

Is this a bug?

eq:=5*x+y-10=0:
eq2:=y=solve(eq,y):

f:=(x,y)->eq2

f(3,1)

I think the way I applied it above is a bit unorthodox to Maple but maybe it is a bug.  Normally I think we use unapply in this situation.

f:=unapply(eq2,x,y)

f(3,1)

Okay better, but I think that first way should work no?

## shading, style and lightmodel oddities...

Maple 2019

choosing lightmodel=none and shading=none, produces a dark grey grided surface
plot3d(x*y, x = 0 .. 10, y = 0 .. 10, lightmodel = none, shading = none)

adding the style=wireframe option gives a blank plot.  Grid probably white?  Changing style to patchnogrid the surface is indeed white. However chosing both shading and style options to none regardless of the lightmodel will produce a plot that appears empty.  Is this to be expected?

However, just the style=wireframe option produces a colored grided wireframe as to expect
plot3d(x*y, x = 0 .. 10, y = 0 .. 10, lightmodel = none, style = wireframe)

## Bug - projection will not work with orie...

Maple 2019

Projection will not work with orientation.

plot3d(x*y, x = 0 .. 10, y = 0 .. 10, projection = 0.2)

plot3d(x*y, x = 0 .. 10, y = 0 .. 10, projection = 0.2, orientation = [55, 75, 0])