Is there any difference between ^ and x_^_ when Pattern Matching any expression that is raised to a power?

err x_^_ and ^

hmm, my syntax isn't being outputted properly

"x_^_" and "^"

nope, this is bizarre, my syntax is being transformed, it's different from what I'm typing.. this makes chatting difficult when talking about programming languages

Use code demarcation with backticks

_^_ vs x_^y_?

yes

how do I demarcate code on stack excahnge?

backticks: `

one on either side of the code

'^ vs x_^_'

!!!

no, that's a regular tick: '

_^_ vs x_^_

right; there's no difference; if you need to use the value of the matched pattern x_ later, you need to give it a name

if you don't care what the value is, you can leave it nameless

ok, thank you Xerx

+0.1 mma skill gain for me

haha, just 1000 more skill until you level up

haha

I've always referred to backticks as tildas, but that's probably a localization issue :D

@AdamDreaver tildes are these guys: ~

@Xerxes ah yah, shift+backtick = tilda

@rm-rf Sent my mom that image you generated :)

@AdamDreaver In the interest of teaching you how to investigate if pattern A and pattern B both match expression C, you can try something like this:

With[{expr = a^b}, {MatchQ[expr, _^_], MatchQ[expr, x_^y_],
  MatchQ[expr, _^y_], MatchQ[expr, x_^_]}]

(of course, make sure x, y, a and b don't have predefined values)

Note that this doesn't necessarily mean that the patterns are the same (in this case they are, if you ignore the naming part)... just that they all match the given input

@rm-rf Thank you my teacher :D This will be very useful throughout my mma learning

Peace be with you

For those that followed my problem of the excel date/time import (depending on time zone, etc), it seems that Mathematica may be right afterwards. When there's a daylight saving, there is actually a clock moment that is either repeated in history (or that doesn't occur, depending if it is summer or winter). Since excel doesn't take this into consideration, the import gets skewed by one hour. This was advanced as a probable cause. When I have the time, I’ll check if the dates match...

By the way, who has already signed for the European Wolfram Technology Conference 2013? It's around Quantity[700 000,"Meters"] away from where I am, so I'll most likely attend.

Damn! My SaveDefinitions inside manipulate stopped working! It was working before, but after some refactoring it stopped completely :(

I'm using a Package I wrote, so I guess this is the problem...

"SaveDefinitions can also be used for function definitions, although it doesn't always reach into packages correctly. Nonetheless, it often works well, and is used in Demonstrations by default."

So Any tips welcome.

Should I generally use With over Module when when I only need local constants and not variables?

@AdamDreaver I'd say if all the variables are CONSTANT that will be used in the expression, then use WITH. If some of them will change, then you have to use Module.

@Nasser well, SWF is a complicated format that does a lot of things; embedded video is just on common use

Mathematica knows how to use SWF for embedded video, but since it doesn't have the full implementation, I guess they figured they wouldn't even try to import it?

I wanted to use M to convert SWF to animated gif file. But I can't even read the swf file !

I thought it will import it, since I can export to SWF.

I am now downloading adbobe FLASH CS6 trial just to do this. I would have like to use M for everything.

It's not always the case that having an exporter implies you can import; you may choose to use only a narrow subset of the format in your exports

Mathematica's support for various imports and exports is certainly very patchy though; I ended up writing my own animated-PNG exporter at one point

@Nasser I 100% understand your answer, ty

Evening people