Thomas Dean

227 Reputation

10 Badges

16 years, 128 days

MaplePrimes Activity


These are replies submitted by Thomas Dean

@Thomas Richard 

I can not reproduce it with the maple gui (xmaple)

This may be due to using maplev-mode with emacs.  I believe that may be a different connection to the server?  Maybe Joe Riel is looking?

Yes, RSA-100 is old.  I was checking some gcc code optimization.

@Thomas Richard 

 

I am using Ubuntu 20.04.   Command line Maple with maplet plotdevice flashes the plot and then closes immediately.

@Thomas Richard 

My startup plot device is maplet.  I mostly use maple 2020.2 with emacs so I need a device other than inliine. If I use xmaple, the gui, plotsetup(default) then plot3d(...) works.

I tried many (all?) of the reasonable devices.  Most return "plotting was not implemented by the application".

With plotsetup(maplet), the plot is displayed briefly and then closes.  The plot seems to be the same as with plotsetup(default).  The error message varies some.

So, this is a bug in maplet?  Looks like maplet is attempting to free an invalid pointer.

@Kitonum 

print(eval(x,eqns)) does it.  This was an attempt to display the results.

@Joe Riel

I got as far as:

restart;
with(Syrup);
ckt := "*\n\
V1 1 0 -10*exp(-2*t)\n\
R1 1 2 2\n\
R2 2 3 2\n\
C1 3 0 0.5F\n\
R3 2 4 4\n\
L1 4 3 1H\n\
.end";

ics := i[R1](0) = 1,  i[R3](0) = -1;
volts, others := Solve(ckt, tran, 'returnall'):
dsol := dsolve(volts);
diff(subs(others, dsol, i[R1](t)), t); evalf(%) ## very different than the OP
diff(subs(others, dsol, i[R3](t)), t);evalf(%)## very different than the OP

## Danialfreddy's solution is (i1 is thru R1 and i2 is thru R3):
diff(i[R1](t),t) = 0.5*i[R1](t) - 3*i[R3](t) + 5*exp(-2*t);
diff(i[R3](t),t) = 2*i[R1](t) - 6*i[R3](t)

 

@acer 

Changing bin/Maple2020.png does not seem to change anything.  Removing bin/Maple2020.png does not change anything.  Seems like twm (or maple) is using a built-in icon?

bin/maple2020.desktop contains

  Icon=/usr/local/maple2020/bin/Maple2020.png

 

 

@acer 

Thanks.

Yes, I made a mistake when entering the plot statement.

 But, changing the plot statement to

b := plot(f, 0..4*Pi, color=white, filled=true):

does not make the 'green' area white.

plotsetup();
preplot = [], postplot = [], plotdevice = maplet, plotoutput = terminal,
plotoptions = ``

f := sin(x);
g := cos(x);
plottools:-transform(unapply([x,y+g],x,y))(plot(f-g,x=0 .. 4*Pi,filled=true));


produces a correct plot.

 

@Joe Riel 

Syrup:-About();

Record(package = "Syrup",version = "1.1.0",author = "Joseph Riel",email =
"jriel@maplesoft.com",date = "2020-02-20",maple = "2018.2")

 

@Joe Riel 

I did not try installing from the cloud before.  Just tried it and it works.

> with(Syrup);
          [Draw, Library, Print, Solve, ToModelica, ToSpice, Version]

> Version;
                                   "0.1.16"

> PackageTools:-Install(6271537930305536,overwrite);
memory used=5.8MB, alloc=40.3MB, time=0.32
                      "/home/tomdean/maple/toolbox/Syrup"

> restart
> ;
> with(Syrup);                                      
           [About, Draw, Library, Print, Solve, ToModelica, ToSpice]

However, About returns nothing.  Seems to solve circuts Ok.

@acer 

Sorry for the omission, but, it did not relate to my original question.

That is: How do I manipulate the expression

y = (sqrt(x) + 10)^(1/3) - (sqrt(x) - 10)^(1/3);

into

y^3 = 20 - 3*(x - 100)^(1/3)*y;

or

y^3 = 20 - 3*(x - 100)^(1/3);  ( I think not possible, except at a specific point)

eq1 := y^3 = 20 - 3*(x - 100)^(2/3);

I can not get from

y = (sqrt(x) + 10)^(1/3) - (sqrt(x) - 10)^(1/3);

to

eq2 := y^3 = 20 - 3*(x - 100)^(1/3)*y;

or, to eq1.

The original problem was for a specific x, x=108.

solve(subs(x=108, eq1),y);

2, -1 - 3    I, -1 + 3    I

solve(subs(x=108, eq2),y);

2, -1 - 3    I, -1 + 3    I

Strange!

@Kitonum 

I got turned around on this and now can not get it straight.

restart;
n:=expand((x-1)*(x-2)*(x-3)); ## zeros
d := solve(n/d = 2-x,d); ## oblique asymptote
eq := n/(d-2); ## why is the denominator off by 2?

plot([eq,2-x], x=-4..8, -5..5,  linestyle=[1,3],color=[red,blue], thickness=[2,0], scaling=constrained);

 

@acer 

Sorry I did not provide the example first.

But, my question was not about the example, but, in finding documentation about the syntax.

I played with the example and understood what it did.

I wanted to discover where things like [a,b](c,d) were documented, hoping I would learn about more things like this.

I guess my question should have been what does maple do when two delimiters, one closing and one opening are adjacent in the input stream.  But, I could not make that link.

Sorry.

@Carl Love 

Other than reading all the help pages, how do I find useful things like this?  I looked in the user manual and programming guide.  Evalapply is in neither.

Tom Dean

@Carl Love 

Sort of an Undocumented short cut?

1 2 3 4 5 Page 1 of 5