Wolfram Mathematica

2:37 AM

@JG What for?

J G

@belisarius web scraping

@JG In Mathematica?

J G

perl

@JG This site is about Mathematica ...

percuße

2:50 AM

@JG you've caused a tiny incident in TeX.SE chat :)

though I still don't get how

I have yet to see a good coding style in the demos, granted I've only seen a few of them so far. Why don't MMA(that's the acronym for mathematica right?) users take advantage of whitespace, indents and newlines to make really readable code?

So far I've only seen code that is densely packed like the programmer had a Guillotine to their throat if they didn't get the code done as quick as possible.

I get the IDE is a little cumbersome, but with a little editing, I'm making the demonstrations I download really readable.

@AdamDreaver Try the workbench

@belisarius I don't know what that is, I'll google it

Oh i see

I'll give it a try, ty you belisarius

@AdamDreaver you're welcome

3:06 AM

belisarius did you see that fourier demo made with mathematica on reddit? I thought it was neat!

@AdamDreaver nope

blog.matthen.com/post/42112703604/…

code for is right on the side, but you seem like you could come up with in your sleep you pro :)

@Adam The front end doesn't make it easy to format code ... you can use the auto-formatting but if you want to change that beyond inserting a few newlines, it becomes painful. And even the newlines are too easily destroyed by copying into a plain text editor and then copying back.

Can be a bit annoying ...

But you can use code-style cells. Press Alt-8 then start typing

@Szabolcs Or forget about it and try to get used to Mma FE coding style

FE coding style? That code-style cell is much nicer than normal input for pure coding

3:17 AM

But coding is not what one usually does in Mathematica.

What does one usually do?

I thought code your math problems to be solved :(

I mean, it's not like writing C or Python: write the program, test the program, correct the program, then put it away for the future.

I usually work "real time", and 90% of what I do is thrown away. E.g. some data needs to be kneaded into a different shape, so I start transforming it by applying functions one by one until I like it, then I plot it, etc.

Can look like magic to those who're not used to it, not having to wait for me to write the program, just stand there and watch it come alive ;-)

@Adam If you write a package that you will re-use often, then I think it's often better to use a plain text editor or the Workbench. The workbench is much better suited for writing big things. The front end is better for quick and dirty stuff, playing, trying out things, and supports graphics of course :)

BTW the reason I love Mathematica is that it makes this type of work possible.

rm -rf

It takes a while for one to get used to the WB, because it is inert (i.e., non-interactive)

@Szabolcs you should do a screencast, I'd love to watch!

you make it sound so organic and awesome

rm -rf

If you get too used to Greek letters, fancy unicode, subscripts, superscripts, etc., you're in for a shock

3:24 AM

@Adam If you use the system daily for a while, you'll soon get used to it, and it'll be the same your you. I'm afraid I made it sound more interesting than it really is. :)

haha

OK, it's late here, I need to go. Good night everyone!

Good night

Guillochon

4:05 AM

Hi all, I'm having problems using Show and RegionPlot together

If I do Show[myregionpl, otherpl], it looks ugly and it seems to turn antialiasing off

If I do Show[otherpl, myregionpl], the region plot shows the mesh, which is also ugly

Heavily related to this question: mathematica.stackexchange.com/questions/1400/…

But it doesn't address how bloody ugly the plots are that show the RegionPlot first!

5:21 AM

if statements r cool functional languages, it's the do/whiles/and fors we want to avoid right?

^cool in functional languages

I guess they must, how else would do you branching code?

5:46 AM

@AdamDreaver Something like this? f[x_] := x^2 /; x > 0; f[x_] := -x^2 /; x < 0; Plot[f@x, {x, -1, 1}]

@belisarius what is the name of that operator, /;

@AdamDreaver Learn how to use the Help System. Highlight it with your mouse and press "F1". ... (Teaching to fish)

Ohh, ty

@AdamDreaver Anyway ... If[] can fit smoothly in a functional style

I think trying to learn functional programming with mathematica might be a mistake for me because of all the imperative syntax; I should of started with haskell or LISP.

5:53 AM

@AdamDreaver Mma isn't only functional. The problem with it is that it implements several paradigms. It isn't a language for learning a paradigm, that's for sure

I was trying to kill two birds with one stone, learn both MMA and functional programming; I'll just separate that learning process. /; is a nice and beatiful, I don't think using an if statement instead of /; would make your example a lot more ugly

Mma is a prgmatic language, not a pure one. It's designed to solve math (and related) problems, not to be a CS playground

@AdamDreaver Oh you're wrong!

not surprised

:)

this stupid wandering cat is distracting me from clear thought, damn it's cuteness

just imagine testing your x values each time you need to use f[x] at your program

@AdamDreaver In Spanish we call "cats" to those women going up and down the street at night

they're distracting also

This is an actual cat, I think I'm infected with that weird cat virus, cats are like sirens to me now. I can't imagine testing my x values. I'd do better thinking if I was in a strip bar.

6:02 AM

@AdamDreaver Actual cats are difficult to point out. How on earth could you know? They don't speak. Has it already declared its true self?

They meow... and I'm pretty sure I know what a cat looks and feels like.

@AdamDreaver That's wishful thinking

@AdamDreaver going back to the If[] problem.

you still here?

aye

All ears

Try thos

ClearAll[f];
f[x_?OddQ] := x;
f[3]

ok will do, I just tried this, f[x_] := If[x > 0, x^2, If[x < 0, -x^2]]; Plot[f@x, {x, -1, 1}], and it has the same results as your /; example, i'll now try what you just posted.

f1 and help IS USEFUL!

6:11 AM

hehe

yup

@AdamDreaver Bookmark this mathematica.stackexchange.com/q/18393/193

@belisarius Done and favorited! tyty

Ok I need to make myself a healthy organic dinner so I can think and be healthy, may you slay any difficult or frustrating work with ease my friend.

@AdamDreaver Go and kill your lettuce in peace

haha :)

9:29 AM

Anyone know how to change the color of comments? it's a dull grey, i want C++ green like comments

Found it!

12:52 PM

@AdamDreaver (Menu) Edit -> Preferences -> Appearance -> Syntax Coloring -> Other -> Cooments ... Check Show Color Spectraand select your lucky color

Q: axis label and ticks alignment of ListPlot3D and Histogram3D

1:02 PM

I can't understand what he wants:

2

I have a question on axis label alignment of ListPlot3D and Histogram3D. These labels are not aligned with the axis of the view, but only horizontally. I have tried very hard to align them manually, but the method sucks and still the output lacks precision and neatness. I wonder if M 9.0.0 has th...

Anyone?

@P.Fonseca Do you?

P. Fonseca

1:23 PM

@belisarius I think he wants the text of the axis labels rotated in alignment with the axis themselves

@P.Fonseca Oh! great! Never thought of that

P. Fonseca

@P.Fonseca Mmm.. I still prefer the labels aligned with me :D

@P.Fonseca since you have generated the images that demonstrate the point exactly, could you edit them into the original question?

@Ajasja Good idea

@Ajasja , @P.Fonseca Done

P. Fonseca

1:41 PM

@belisarius thank you...

@P.Fonseca Edit it if my update doesn't fit your taste

1:55 PM

Hey, I have a expression like this:
List[Rule[PlotLabel,Style["{2004, 1, 1, 0, 0, 0.} - {2005, 7, 14, 0, 0, 0.}",Bold]]]

How can I get only this part {2004, 1, 1, 0, 0, 0.} - {2005, 7, 14, 0, 0, 0.}?

I tried ReplaceAll but it doesn't want to work.

@crobartie Try with Part

exp = List[
  Rule[PlotLabel,
   Style["{2004, 1, 1, 0, 0, 0.} - {2005, 7, 14, 0, 0, 0.}", Bold]]]

exp[[1, 2]]

Ok.

@Ajasja That work List[Rule[PlotLabel,Style["{2004, 1, 1, 0, 0, 0.} - {2005, 7, 14, 0, 0, 0.}",Bold]]][[1,2,1]] but I get "{2004, 1, 1, 0, 0, 0.} - {2005, 7, 14, 0, 0, 0.}"

@Ajasja I want 2 lists from that (not a String)

Well you said
>How can I get only this part {2004, 1, 1, 0, 0, 0.} - {2005, 7, 14, 0, 0, 0.}?

2:12 PM

@Ajasja My error :/

@Ajasja I think StringSplit@str will be ok..

@crobartie Yup. And you can use ToExpression on each part of the string to get the lists, if you need them as lists.

@Ajasja Thank you! :)