taro

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6 years, 231 days
Maple is to me difficult. The first version I bought was Maple9, and it was more than 15 years ago. But, I couldn't use it, feeling it too difficult. But, three years ago, I thought Maple might be helpful to my study, and since then, I have continued to learn Maple. As I got able to read the Maple help, I think that I could get to use maple better now than before. But, I feel that I am a beginner yet.

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These are questions asked by taro

Hello people in mapleprimes,

I am writing this sentences, hoping to be given any answer from you, to the 
question I have, about conversion of Array to List.

restart;
a:=plot3d(theta*z,theta=0..2,z=0..1,coords=cylindrical,grid=[3,2]);
A:=op([1,1],a);

brings a response of Array as, which I call BB,

Array(1 .. 3, 1 .. 2, 1 .. 3, {(1, 2, 3) = HFloat(1.), (2, 2, 1) = HFloat(.540302305868139765), (2, 2, 2) = HFloat(.841470984807896505), (2, 2, 3) = HFloat(1.), (3, 2, 1) = HFloat(-.832293673094284814), (3, 2, 2) = HFloat(1.81859485365136342), (3, 2, 3) = HFloat(1.)}, datatype = float[8])

And, I converted it to List, with 

convert(A,list,nested);

The response of this is, which I call CC,

[[[0., 0., 0.], [0., 0., 1.]], [[0., 0., 0.], [.540302305868140, .841470984807897, 1.]], [[-0., 0., 0.], [-.832293673094285, 1.81859485365136, 1.]]]

, which is composed of three lists:
[[0., 0., 0.], [0., 0., 1.]]

[[0., 0., 0.], [.540302305868140, .841470984807897, 1.]]

[[-0., 0., 0.], [-.832293673094285, 1.81859485365136, 1.]]

Then, my question is following:

Seeing CC, I can see three segments are shown.
The first one is  the segment between [0., 0., 0.] and [0., 0., 1.].
But, I can't find any elements of Array BB corresponding to [0,0,0] above in CC.
And as for 0, 0 in [0, 0, 1] in CC above, the first 0 should be (1,2,1) and the second one should be (1,2,2).
But, there are no such (1,2,1) and (1,2,2) in BB. 
Despite of these, BB is converted to CC, from any reason I want to know and ask this question for.

As for [[0., 0., 0.], [.540302305868140, .841470984807897, 1.]] in BB, the circumstances are the same.
I don't know from where [0,0,0] appeared. Surely, as MESH requires three points, you might say that
such things might occur. But, it is only after I converted Array BB to List CC, with plot3d or MESH then having no relation 
to the present circumstances. So, I think that it is not possible to say that Maple added [0,0,0] or such things to Array BB

 as it is about plot 3D or about MESH.

So, my question is how the conversion of BB to CC could have occurred.

Thanks in advance.

May_16_2018_question.mw

Hello people in mapleprimes,

I am writing this question, hoping you to teach me about the meanig of the Array in a plot3d object.

c:=plot3d(x*y,x=0..2,y=0..1,coords=cylindrical,grid=[3,2]);
lprint(c);

makes 

PLOT3D(MESH(Array(1 .. 3, 1 .. 2, 1 .. 3, {(1, 2, 3) = HFloat(2.), (2, 2, 1) = HFloat(1.08060461173627953), (2, 2, 2) = HFloat(1.68294196961579301), (2, 2, 3) = HFloat(2.), (3, 2, 1) = HFloat(-1.66458734618856963), (3, 2, 2) = HFloat(3.63718970730272684), (3, 2, 3) = HFloat(2.)}, datatype = float[8])))

I thought I had known the cylindrical coords.
And, I think that (1, 2, 3) in  (1, 2, 3) = HFloat(2.) means the value of x*y when x, the angle, =0, y, the hight, =1, z, distance from the origin, =3. And, it should become 0, as the value of x, times 1, the value of y, equals 0. But, it takes HFloat(2.) as
shown in (1, 2, 3) = HFloat(2.).

And, as for (3, 2, 1) = HFloat(-1.66458734618856963), which means x=2 and y=1, I think the value of x*y=2. But, 
it is wrong as seen in  (3, 2, 1) = HFloat(-1.66458734618856963). 

I hope you will teach me how to consider about sample points in the cylindrical plot.

Thank you advance.

 

 

 

 

Hello people in mapleprimes,

This time question is a sequel of the previous one:
https://www.mapleprimes.com/questions/224346-Batch-File-And-Directory
, where I could obtain the file with the output.
Maple has been terminated after exhausting the output file.

But, I want  to do the next calculation while using the result in the output file.
For that, I think it might be a good way to have maple calculate a mpl file again, after having added 
new expressions to the original mpl file. But, copying and pasting expressions seen in the output file to the original mpl file with my hand, seems a little messy.

So, what I want to know is whether there isn't a good way for continuing calculations one after another,
while having maple termination after each calculation.

I will be very glad if you will give me an answer to this question.

 Thanks in advance.

Hello people in mapleprimes,
I have two files: a batchfile named test.command, and a mpl file,
both in <<my home directory>>.

And, the codes written there are, for the test.command,

/Library/Frameworks/Maple.framework/Versions/2017/bin/maple test.mpl > output.txt

And, for the mpl file,

1+1;
diff(x^2,x);
int(x^3,x);

The test.command was made executable with chmod u+x  test.command, in advance.

From my home directory, I can run the test.command, and obtain output.txt with the result of the calculation of 
the mpl file. The above things have no problem. 

My question is a following.

When I moved the two files, the batch file and the mpl file, to /Users/myname/Desktop/maple_test, 
I cannot get maple to exhaust the appropriate output.txt but an error message, saying it could not read the mpl file.
What should be done to the contents of two files?

I hope you will teach me about this.

Thanks in advance.

taro

 

 

 

Hello people in mapleprimes,

I am reading Introduction to Maple. There, the following input and output appear.

> convert((-8)^(1/3), RootOf);
1+RootOf(_Z^2 + 3, index = 1)

I think, which implies

beta^3+8=0

and

with the solution alpha of alpha^2+3=0, beta above is expressed as 1+alpha.

But, probably from my understanding being wrong, I can't understand why this becomes so.

So, though this is about mathematics, not about maple, if possible, can I ask you to teach me why

convert((-8)^(1/3), RootOf) brings 1+RootOf(_Z^2 + 3, index = 1)?

Thanks in advance.

 

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