Wolfram Mathematica

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1:28 PM

@Kuba Re. this, sure that's how the question read, but that could just be a clever way of making the question on topic. e.g. if I don't know how to plot a spiral because I don't know the equation, then I could just pretend that I don't know how ParametricPlot works, even though I know that.

I'm not sure "I can't solve this because I don't know enough about ParametricPlot" counts as an attempt since he doesn't detail what it is he doesn't know about ParametricPlot that would enable him to solve the problem, if he knew it.

And that was my point; he says he could solve the problem if he knew more about ParametricPlot, but he doesn't pose that problem. Instead he poses a less specific, less Mathematica-related problem.

2 hours later…

Kuba

3:27 PM

@C.E. I wasn't clear :) My point was that most of his questions is about math more than about mathematica. e.g. 124880 I have already told him that those questions are really about basic linear algebra but noone cares :) On the other hand community enjoy, he is polite and accepts, so I just don't comment anymore :)

Rojo

3:59 PM

Hey guys

Do you reproduce this disgusting bug?

Compile[{{x, _Real}}, Log[x], CompilationTarget -> "C"]

Log turned into Exp

C. E.

@Kuba ok, then we think alike. I should probably try to avoid commenting as well.

@Rojo Nope, Log is Log for me. V. 11.0.0.0

Rojo

@C.E. Oh. Are you using CompilationTarget -> "C"?

Because inspecting with CompilePrint gives Exp in both cases but using it only gives Exp with C

C. E.

Yes, with or without it works as Log and CompilePrint says it's log (screenshot: i.stack.imgur.com/iLo9Z.png).

Rojo

@C.E. ok, thanks. It seems it was fixed in the release :)

Nice

C. E.

Experts in Fourier transform filtering and image processing, please take a look at this question:

Q: How to place curve path lines on an image

This is a further question of this post.I just make the path be curve by Photoshop. I note Mr. C.E.'s method seem to not work anymore.Any method can repair it? Since I posted the original question, I believe I should provide the curved path image as well. So, here goes an original image with ...

image-processing

It's a problem that me, Yode, and FACamargo have been occupied with for a couple of days now.

Rojo

4:14 PM

Now that you helped me, I have to take a look even if I'm not an expert

xslittlegrass

4:50 PM

A quick question:

In[1]:= f[] := Module[{},
$x = 1;
$x
]

In[2]:= g[x_: $x] := x

In[3]:= g[2]

Out[3]= 2

In[4]:= f[]

Out[4]= 1

In[5]:= g[x]

Out[5]= x

why do I get x instead of 1?

Is there a way to force g to use the current $x value ?

I found the answer

Q: Specifying optional arguments with variables

Perhaps this is poor programming on my part, but I would like to create a function that uses a variable as an optional parameter: var = 2; f[a_:var] := {a} The desired output would be: f[] (* {2} *) var = 5; f[] (* {5} *) However the optional a maintains the value of var when f was defined:...

function-construction variable-definitions optional-arguments

2 hours later…

JasonB

7:04 PM

Anybody here use JLink` regularly?
I'm wondering how best to use non-static methods without having their names creep into the ``Global` `` context

er, Global`

Wolfram Blog

Wolfram Blog: New in the Wolfram Language: Audio

posted on September 23, 2016 by Carlo Giacometti

I have always liked listening to music. In high school, I started wondering how it is that music seems to be so universally pleasing, and how it differs from other kinds of sounds and noises. I started learning to play guitar, and later at the University of Trieste, I learned about acoustics and signal processing. [...]

JasonB

I load a class, use the static getInstance[] method to create an object, and when I use a non-static method (the kind where you need an @ to access it in MMA), the name of the method is in blue, but afterward it is a symbol

like
LoadJavaClass["my.class"]
obj = my`class`getInstance[];
obj@nonStaticMethod[]
Context[nonStaticMethod]
(* Global` *)

JasonB

7:28 PM

Probably the answer is just to only call these methods inside the private context of a package

2 hours later…

Michael Hale

9:17 PM

So if I deploy something to the cloud is there a way to prevent someone I send the link to from just clicking the cell and pressing delete and then the content is deleted for everyone?

Or is that just because I'm the owner that I can do that. One sec.

JasonB

@MichaelHale "CloudShare by default sets permissions to Automatic, allowing reading or execution as appropriate"

But looking at SetPermissions, it looks like you can modify them

Michael Hale

@JasonB Ah cool. Yes "Public" defaults to owner {read, write, execute}, all {read}.

1 hour later…

Michael Hale

10:25 PM

Not as cool. I tried deploying something that read from a very simple CloudExpression object. It worked in notebook. In browser it got stuck in a reading cycle and ate 1/4 of my cloud credits.