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2018-08-31 21:38:39 -0500 commented answer Conflicting Sage vs Wolfram evaluation of a limit?

Thanks -- that is good to know! Now I just need to know how to get Sage to compute the correct limit (i.e. Limit[V[a,w], a -> Infinity] should output $0$ instead of its current output of $1$).

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2018-08-29 12:10:33 -0500 commented answer Conflicting Sage vs Wolfram evaluation of a limit?

The point is that the limit is computed to be 1 by Sage and 0 by Wolfram, in spite of the unstable behavior indicated by the plots. (I've edited to clarify.)

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2018-08-29 09:17:24 -0500 asked a question Conflicting Sage vs Wolfram evaluation of a limit?

>Why are the following computed limits different (1 by Sage, 0 by Wolfram), and which (if either) is correct?

EDIT: Increasing the numerical precision in Wolfram produces a plot that strongly suggests that the limit is indeed $0$, which it had already computed. Presumably, Sage is computing the wrong limit simply because of inadequate numerical precision, so the question is now ...

How can I increase the numerical precision in Sage, so that limit() and plot() will produce the correct results (i.e., the limit should be $0$ and the plot should show a stable approach to $0$)?

Sage: (you can cut/paste/execute this code here)

#in()=
f(x) = exp(-x^2/2)/sqrt(2*pi)
F(x) = (1 + erf(x/sqrt(2)))/2
num1(a,w) = (a+w)*f(a+w) - a*f(a)
num2(a,w) = f(a+w) - f(a) 
den(a,w) = F(a+w) - F(a)
V(a,w) = 1 - num1(a,w)/den(a,w) - (num2(a,w)/den(a,w))^2
assume(w>0); print(limit(V(a,w), a=oo))
plot(V(a,1),a,0,8)

#out()=
1        #<--------- computed limit = 1

enter image description here

Wolfram: (you can execute this code here)

#in()=
f[x_]:=Exp[-x^2/2]/Sqrt[2*Pi]
F[x_]:=(1 + Erf[x/Sqrt[2]])/2 
num1[a_,w_] := (a+w)*f[a+w] - a*f[a]
num2[a_,w_] := f[a+w] - f[a]  
den[a_,w_] := F[a+w] - F[a]
V[a_,w_] := 1 - num1[a,w]/den[a,w] - (num2[a,w]/den[a,w])^2 
Assuming[w>0, Limit[V[a,w], a -> Infinity]]
Plot[V[a, 10], {a, 0, 100}, WorkingPrecision -> 128] 

#out()=
0        (* <--------- computed limit = 0 *)

enter image description here

(This is supposed to compute the limit, as a -> oo, of the variance of a standard normal distribution when truncated to the interval (a,a+w).)

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2018-05-27 10:46:07 -0500 commented answer Running Sagemath 8.2 natively in Windows, how to change the Jupyter default directory?

Thank you! That seems to be working after I changed my directory names to remove all spaces from them.

2018-05-27 10:01:50 -0500 commented answer Running Sagemath 8.2 natively in Windows, how to change the Jupyter default directory?

This is along the lines I'd hoped for, but unfortunately it doesn't work. (I also tried it using an equals sign: --notebook-dir=directory_name.)

2018-05-26 21:59:30 -0500 asked a question Running Sagemath 8.2 natively in Windows, how to change the Jupyter default directory?

With SageMath 8.2 running natively under Windows 10, the Jupyter dashboard opens by default in the directory C:\Users\<me>, so I then have to navigate to the desired directory that contains my Jupyter notebook .ipynb files.

How can I cause Jupyter to open directly in the desired directory?

The relevant Windows shortcut has the following Target Property:

"C:\Program Files\SageMath 8.2\runtime\bin\mintty.exe" -t 'SageMath 8.2 Notebook Server' -i sagemath.ico /bin/bash --login -c '/opt/sagemath-8.2/sage --notebook jupyter'

Can the sage --notebook jupyter portion be adjusted somehow to specify the desired directory?

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2017-11-10 22:55:35 -0500 commented answer Running natively in Windows, can a SageMath 8.0 Jupyter Notebook access "legacy" .sws worksheets

Thanks for your answer. When I make the change you suggest, the shortcut opens a page that says "Convert old notebooks to Jupyter ... Click on any of the notebooks below to convert it to a new Jupyter notebook and open it in Jupyter: ...". ---Unfortunately, the list of notebooks to be converted is empty.

What should I do to make this page recognize & convert my .sws files?

NB: My collection of .sws files currently exists in two forms: (1) a .zip file that I downloaded from a SageMath 6.8 Notebook, and (2) the files resulting from uploading said .zip file into a SageMath 8.0 Notebook (SageNB). (I'm unsure where these latter files are located, but I suspect they're in the many subfolders of C:\Users\<myusername>\.sagemath-8.0\sage_notebook.sagenb\home\__store__

2017-11-10 03:50:53 -0500 asked a question Running natively in Windows, can a SageMath 8.0 Jupyter Notebook access "legacy" .sws worksheets

As a Windows 10 user, I recently upgraded from SageMath 6.8 running in VirtualBox to SageMath 8.0 running natively without VirtualBox. I successfully uploaded my "library" of hundreds of .sws worksheets into a SageMath 8.0 "legacy" (SageNB) Notebook (*). But my question is as follows:

Is there a way to upload my "library" of .sws worksheets into a Jupyter Notebook in SageMath 8.0 running natively in Windows?

(*) I noticed that on my system, the Windows 10 shortcut produced upon installing SageMath 8.0 had the following target for opening a Jupyter Notebook: "C:\Program Files\SageMath 8.0\runtime\bin\mintty.exe" -t 'SageMath 8.0 Notebook Server' -i sagemath.ico /bin/bash --login -c '/opt/sagemath-8.0/sage --notebook jupyter'

By simply replacing that last word jupyter with sagenb (and renaming the shortcut), I obtained a shortcut that opens a "legacy" SageMath Notebook (SageNB). This, rather than a Jupyter Notebook, is the only way I've so far managed continue using my "library".