nm

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These are questions asked by nm

I googled, read help and not able to find how to do this. 

I want to change the zoom in worksheet to any value I want, and not just 100%,150%,75%, etc.... which are the values that are listed in View->Zoom factor.

Is there a place one can type in the zoom value they want? Say 110% or any other number?

windows 10.

Thank you

I read a string from file which contains a sequence of Maple commands, all in one string. The commands are separated by ";" in the string. I need to then evaluate all the commands in the string as if I typed them one after the other. 

Here is an example

data:="x:='x';y:='y';sol:=dsolve(diff(y(x),x)=1,y(x));"; #read from database
parse(data);

Warning, extra characters at end of parsed string
x := 'x'
 

I want the result to parse to be as if I typed

x:='x'; 
y:='y'; 
sol:=dsolve(diff(y(x),x)=1,y(x));

I looked at help in parse page, but I do not see what I need to do. It says that 

If the option 'statement' is specified, the string must consist of exactly one Maple statement (which includes expressions). The statement is parsed and evaluated, and the result is returned.
 

But I am not using the statment option. I also tried using this option, no change, same problem.

Is there a way to prase such a string? 

Thanks

 

Is this documenation wrong?

https://www.maplesoft.com/support/help/maple/view.aspx?path=Database%2fSQLite%2fFetchRow

It says that calling sequence is 

     FetchRow( statement, column, valuetype  )

But below it only shows 

statement

-

prepared statement obtained using Prepare command

valuetype

-

type of the output data, default is "auto"

 

With no column anywhere.  And none of examples show column in them.

And when I tried it by adding a column name that I know exist in my sqlite3 database, Maple gave an error that no such parameter allowed.  

Does FetchRow support column name or is the above just a documenation error?

Maple 2019

 

Hello Maple experts;

I am not able to understand why Maple 2019 can solve Laplace PDE in 2D Catersian on semi-infinite domain, when the infinity is along the Y direction, but not along the X direction, since the solution method is exactly the same.

Here is the code

restart;

#right one, Maple can not solve
pde := diff(u(x, y), x$2)+diff(u(x, y), y$2) = 0:
bc_left_edge := u(0, y) = 0:
bc_bottom_edge:= u(x, 0) = 0:
bc_top_edge:= u(x, 1) = A:
bc:=bc_left_edge ,bc_top_edge,bc_bottom_edge:
sol:=pdsolve([pde, bc],HINT = boundedseries(x = infinity)) assuming x>0,y>0;


#left one, Maple can solve
pde := diff(u(x, y), x$2)+diff(u(x, y), y$2) = 0:
bc_left_edge := u(0, y) = 0:
bc_bottom_edge:= u(x, 0) = 0:
bc_right_edge:= u(1, y) = A:
bc:=bc_left_edge ,bc_right_edge,bc_bottom_edge:
sol:=pdsolve([pde, bc],HINT = boundedseries(y = infinity)) assuming x>0,y>0;

Here is screen shot.

Maple can solve both cases if I remove the HINT. But the solution it gives is not as simple as using the HINT and contains unknown constants (_C5) that is why I use the HINT.

But the main question is, since both problems are exactly the same, why Maple can solve one and not the other when using the HINT? Is there something I am doing wrong? 

Maple 2019 on windows 10 and Physics cloud version 333.

Thank you

This is a minor issue, but I noticed using Maple 2019, with Physics cloud version 331 that it prints on the screen some results from internal computation on some calls to pdsolve

I have a ":" at the end of each command, so no output should go to the screen. In Maple 2018 this does not happen.

 

pde := a*diff(w(x,y),x) +  b*arctan(lambda*y)*diff(w(x,y),y) =  a*arctan(mu*x)^m+arctan(beta*y)^k:
sol := pdsolve(pde,w(x,y)):

#another example

pde := a*diff(w(x,y),x) +  b*arccot(lambda*y)*diff(w(x,y),y) =  a*arccot(mu*x)^m+arccot(beta*y)^k:
sol:=pdsolve(pde,w(x,y)):

Running the above on Maple 2019 and Maple 2018, here is screen shot. Notice the output in Maple 2019

 

In Maple 2019

 

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