|
Thread Rules
1. This is not a "do my homework for me" thread. If you have specific questions, ask, but don't post an assignment or homework problem and expect an exact solution.
2. No recruiting for your cockamamie projects (you won't replace facebook with 3 dudes you found on the internet and $20)
3. If you can't articulate why a language is bad, don't start slinging shit about it. Just remember that nothing is worse than making CSS IE6 compatible.
4. Use [code] tags to format code blocks. |
On April 17 2017 03:17 dsyxelic wrote:
Question about android studio: how good of a computer do you or should you have to not have it lag? Did some android projects for a class and almost everybody reported it was extremely laggy besides like mac users. Id want to do more android work but I just cant deal with the lag on my machine and the specs arent that bad... I even used a separate emulator (genymotion) and other settings tricks off google to minimize lag to no avail.
It's a matter of settings for the jetbrains products most of the time. You should set your caches etc. to reasonable levels so the indexing and garbage collection don't take as much time. Another trick I've learned in their products (which are awesome) is checking the "display memory usage" or somesuch option in the menu. Then you get this small bar in the bottom right that shows how much of the allowed memory your IDE is currently using and you can click on it to trigger immediate garbage collection (which drops it down from 1GB to 100MB instantly for example).
I'll post the correct settings on tuesday, when I'm back at my workstation.
|
as an IDE, android studio (or in fact, IntelliJ) is fantastic. But the actual Android tools worked better from their eclipse-based Android SDK. Any time I click an android-related button my computer lags out and in addition Gradle builds take FOREVER (I want Ant back, it was buggy every now and then, but at least it was fast). But it is what it is.
|
On April 17 2017 03:35 Manit0u wrote:Show nested quote +On April 17 2017 03:17 dsyxelic wrote:
Question about android studio: how good of a computer do you or should you have to not have it lag? Did some android projects for a class and almost everybody reported it was extremely laggy besides like mac users. Id want to do more android work but I just cant deal with the lag on my machine and the specs arent that bad... I even used a separate emulator (genymotion) and other settings tricks off google to minimize lag to no avail. It's a matter of settings for the jetbrains products most of the time. You should set your caches etc. to reasonable levels so the indexing and garbage collection don't take as much time. Another trick I've learned in their products (which are awesome) is checking the "display memory usage" or somesuch option in the menu. Then you get this small bar in the bottom right that shows how much of the allowed memory your IDE is currently using and you can click on it to trigger immediate garbage collection (which drops it down from 1GB to 100MB instantly for example). I'll post the correct settings on tuesday, when I'm back at my workstation.
Ah thanks, hopefully that saves my lag. And yes I agree the IDE itself is great, just the darn lag 
|
I'd avoid using an emulator if possible. Much better experience with a device.
|
On April 17 2017 07:11 Blisse wrote:
I'd avoid using an emulator if possible. Much better experience with a device.
Using apk + device?
Also do you mean the inbult emulator or all emulators in general? Genymotion seemed decent from the few times I used it and a lot more lightweight
|
On April 17 2017 09:32 dsyxelic wrote:Show nested quote +On April 17 2017 07:11 Blisse wrote:
I'd avoid using an emulator if possible. Much better experience with a device. Using apk + device? Also do you mean the inbult emulator or all emulators in general? Genymotion seemed decent from the few times I used it and a lot more lightweight
Not really sure what you mean by using apk + device... but yes, you plug your device to your computer(or set-up adb over tcp), run, and choose to deploy to your device, which yes, puts and runs the apk on your device.
I'm not sure what's is the current state of emulators... because in 3 years I've never used an emulator at work or aside. I think genymotion was the last emulator I used and it was decent versus the built-in emulator with Eclipse.
I see no reason to use an emulator if I could use a device, unless you're doing some non-standard stuff. Unless you have a good desktop or high-end laptop, things aren't going to run as well, with the emulator competing with Android Studio and what not for resources. And you're going to have to test on your phone eventually anyways.
|
ah yeah thats what I meant.I actually did it the long way by simply downloading the .apk file and running it on my phone... didn't know you could deploy straight to device
I'll try that too. Never crossed my mind because we had to present using an emulator heh.
|
On April 17 2017 13:13 dsyxelic wrote:
ah yeah thats what I meant.I actually did it the long way by simply downloading the .apk file and running it on my phone... didn't know you could deploy straight to device
I'll try that too. Never crossed my mind because we had to present using an emulator heh.
I agree with Blisse. The two are incomparable, and you'll have a far better experience debugging on a device. However, for UI things, you are almost required to emulate (or have phones and tablets of all shapes and resolutions you want to be compatible with). Similar for backward compatibility (or forward): if you configure your project right, it shouldn't be an issue, but shouldn't and won't are worlds apart.
The built-in emulator is not very good, but adb plays nice with it. Presumably you can get logcat to connect to genymotion, but can you also do that with the debugger? If so, that's a better option. But you definitely want an emulator you can debug on. Despite the advice to do most of your testing on an actual phone.
|
gotcha
i'll prob just use genymotion for the emulator needs
i've only had good experiences with it and lag was cut down considerably with it. my only lag currently comes from the IDE itself (and if I use the built in emulator which I haven't for a while).
|
I'd like to check some stuff from my combinatorics/probability homework if anyone is willing to take a look
But first I need help understanding a question
+ Show Spoiler +
Let A_1, . . . , A_n be sets such that there exist numbers N_1, . . . , N_n such that:
For all 1 ≤ k ≤ n, for all i_1 < i_2 < · · · < i_k
| A_i1 ∩ A_i2 ∩ · · · ∩ A_ik | = N_k.
Write the law of inclusion and exclusion for A_1, . . . , A_n BUT (for example) instead of having clumsy terms like
|A1 ∩ A2 ∩ A3| you’ll have N_3.
SO- it should have the form
|A1 ∪ · · · ∪ An| = A FUNCTION OF N_1, . . . , N_n
There were other questions like this.. and I understood them.
But i don't understand this at all.
it just doesn't make sense to me
checking some other stuff:
+ Show Spoiler +
You have a deck with 20 ranks, 3 suits (so 60 cards total). A "hand" is 6 cards.
What is the odds of getting a hand of all primes of the same suit?
I put:
3*(8 choose 6) / (60 choose 6)
60 choose 6 is my denominator for all of this because that is the total possible hands dealt
for the numerator there is 8 ranks that are primes and i am picking 6 of them. Then there are also 3 different suits where I can do this, so that is why I multiply by 3.
odds of getting all primes?
(24 choose 6) / (60 choose 6)
24 different primes, you pick 6 of them
odds of getting 6 primes all of different ranks?
I am not really sure about this one. I am thinking my numerator could be:
24*21*18*15*12*9 - but they don't want us to do it this way.
I also think I could do it as [(24 choose 6) - pairs and triplets], but I am not sure how to do that. so yeah could use help here
odds of getting a "6 card straight all of the same suit" ?
1-6 up to 15-20 = 15 possible straights, over 3 suits. 3 * 15 = 45
45/(60 choose 6)
odds of getting a "6 card straight but not all of the same suit?"
[15*3^6 / (60 choose 6) ] - odds of the last question
15 possible starting ranks, then pick each card 6 times out of 3 available suits
last thing to check is a bayes problem
+ Show Spoiler +
we have 2 coins. a fair one and a biased one
the biased one comes up H 9/10, and T 1/10
we pick a coin at random, flip it twice.
what is the odds the coin is biased if it comes up Heads and then tails?
I did .5(9/100)/.5(9/100+1/4)
which is: odds of it being biased * (odds of it being heads if it is biased * odds of it being tails if it is biased)
over
(odds of it being biased) * (odds of it being heads if it is biased * odds of it being tails if it is biased) * odds of it being fair * (odds of it being heads if its fair * odds of it being tails if it is fair)
with some algebra i get: 1/(1 + 25/9) which sounds about right i guess
|
On April 17 2017 07:07 dsyxelic wrote:Show nested quote +On April 17 2017 03:35 Manit0u wrote:On April 17 2017 03:17 dsyxelic wrote:
Question about android studio: how good of a computer do you or should you have to not have it lag? Did some android projects for a class and almost everybody reported it was extremely laggy besides like mac users. Id want to do more android work but I just cant deal with the lag on my machine and the specs arent that bad... I even used a separate emulator (genymotion) and other settings tricks off google to minimize lag to no avail. It's a matter of settings for the jetbrains products most of the time. You should set your caches etc. to reasonable levels so the indexing and garbage collection don't take as much time. Another trick I've learned in their products (which are awesome) is checking the "display memory usage" or somesuch option in the menu. Then you get this small bar in the bottom right that shows how much of the allowed memory your IDE is currently using and you can click on it to trigger immediate garbage collection (which drops it down from 1GB to 100MB instantly for example). I'll post the correct settings on tuesday, when I'm back at my workstation. Ah thanks, hopefully that saves my lag. And yes I agree the IDE itself is great, just the darn lag
Ok, here goes. You can access it via Help -> Edit Custom VM Options... (or Edit Custom Properties)
-Xms2048m
-Xmx2048m
-XX:MaxPermSize=1024m
-XX:ReservedCodeCacheSize=240m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-ea
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-XX:+HeapDumpOnOutOfMemoryError
-XX:-OmitStackTraceInFastThrow
-Dawt.useSystemAAFontSettings=lcd
-Dsun.java2d.renderer=sun.java2d.marlin.MarlinRenderingEngine
You can tinker around with it. I've heard people had different results with different memory settings (sometimes lower is somehow better for compilation time etc. and I don't really know why).
|
On April 18 2017 04:18 travis wrote:I'd like to check some stuff from my combinatorics/probability homework if anyone is willing to take a look But first I need help understanding a question + Show Spoiler +
Let A_1, . . . , A_n be sets such that there exist numbers N_1, . . . , N_n such that:
For all 1 ≤ k ≤ n, for all i_1 < i_2 < · · · < i_k
| A_i1 ∩ A_i2 ∩ · · · ∩ A_ik | = N_k.
Write the law of inclusion and exclusion for A_1, . . . , A_n BUT (for example) instead of having clumsy terms like
|A1 ∩ A2 ∩ A3| you’ll have N_3.
SO- it should have the form
|A1 ∪ · · · ∪ An| = A FUNCTION OF N_1, . . . , N_n
There were other questions like this.. and I understood them. But i don't understand this at all. it just doesn't make sense to me
What is being asked is to give a general formula for the rank of the union of A1... An, but using the numbers Ni. However, your notation is a bit confusing. I'm assuming that the ranks of all Ai are the same, and furthermore the ranks of all intersections are the same, e.g.: |A1| = |A2|, but also |A1 ∩ A2| = |A2 ∩ A3|
In that case, it's fairly easy. Here it is for n=2, but it's trivial to write it for any general n using the general formula for the inclusion-exclusion principle.
|A1 ∪ A2| = |A1| + |A2| - |A1 ∩ A2| = N1 + N1 - N2 = 2N1 - N2
checking some other stuff: + Show Spoiler +
You have a deck with 20 ranks, 3 suits (so 60 cards total). A "hand" is 6 cards.
What is the odds of getting a hand of all primes of the same suit?
I put:
3*(8 choose 6) / (60 choose 6)
60 choose 6 is my denominator for all of this because that is the total possible hands dealt
for the numerator there is 8 ranks that are primes and i am picking 6 of them. Then there are also 3 different suits where I can do this, so that is why I multiply by 3.
odds of getting all primes?
(24 choose 6) / (60 choose 6)
24 different primes, you pick 6 of them
odds of getting 6 primes all of different ranks?
I am not really sure about this one. I am thinking my numerator could be:
24*21*18*15*12*9 - but they don't want us to do it this way.
I also think I could do it as [(24 choose 6) - pairs and triplets], but I am not sure how to do that. so yeah could use help here
odds of getting a "6 card straight all of the same suit" ?
1-6 up to 15-20 = 15 possible straights, over 3 suits. 3 * 15 = 45
45/(60 choose 6)
odds of getting a "6 card straight but not all of the same suit?"
[15*3^6 / (60 choose 6) ] - odds of the last question
15 possible starting ranks, then pick each card 6 times out of 3 available suits
last thing to check is a bayes problem + Show Spoiler +
we have 2 coins. a fair one and a biased one
the biased one comes up H 9/10, and T 1/10
we pick a coin at random, flip it twice.
what is the odds the coin is biased if it comes up Heads and then tails?
I did .5(9/100)/.5(9/100+1/4)
which is: odds of it being biased * (odds of it being heads if it is biased * odds of it being tails if it is biased)
over
(odds of it being biased) * (odds of it being heads if it is biased * odds of it being tails if it is biased) * odds of it being fair * (odds of it being heads if its fair * odds of it being tails if it is fair)
with some algebra i get: 1/(1 + 25/9) which sounds about right i guess
Only really skimmed this, but it generally seems ok.
|
On April 18 2017 04:18 travis wrote:I'd like to check some stuff from my combinatorics/probability homework if anyone is willing to take a look But first I need help understanding a question + Show Spoiler +
Let A_1, . . . , A_n be sets such that there exist numbers N_1, . . . , N_n such that:
For all 1 ≤ k ≤ n, for all i_1 < i_2 < · · · < i_k
| A_i1 ∩ A_i2 ∩ · · · ∩ A_ik | = N_k.
Write the law of inclusion and exclusion for A_1, . . . , A_n BUT (for example) instead of having clumsy terms like
|A1 ∩ A2 ∩ A3| you’ll have N_3.
SO- it should have the form
|A1 ∪ · · · ∪ An| = A FUNCTION OF N_1, . . . , N_n
There were other questions like this.. and I understood them. But i don't understand this at all. it just doesn't make sense to me checking some other stuff: + Show Spoiler +
You have a deck with 20 ranks, 3 suits (so 60 cards total). A "hand" is 6 cards.
What is the odds of getting a hand of all primes of the same suit?
I put:
3*(8 choose 6) / (60 choose 6)
60 choose 6 is my denominator for all of this because that is the total possible hands dealt
for the numerator there is 8 ranks that are primes and i am picking 6 of them. Then there are also 3 different suits where I can do this, so that is why I multiply by 3.
odds of getting all primes?
(24 choose 6) / (60 choose 6)
24 different primes, you pick 6 of them
odds of getting 6 primes all of different ranks?
I am not really sure about this one. I am thinking my numerator could be:
24*21*18*15*12*9 - but they don't want us to do it this way.
I also think I could do it as [(24 choose 6) - pairs and triplets], but I am not sure how to do that. so yeah could use help here
odds of getting a "6 card straight all of the same suit" ?
1-6 up to 15-20 = 15 possible straights, over 3 suits. 3 * 15 = 45
45/(60 choose 6)
odds of getting a "6 card straight but not all of the same suit?"
[15*3^6 / (60 choose 6) ] - odds of the last question
15 possible starting ranks, then pick each card 6 times out of 3 available suits
last thing to check is a bayes problem + Show Spoiler +
we have 2 coins. a fair one and a biased one
the biased one comes up H 9/10, and T 1/10
we pick a coin at random, flip it twice.
what is the odds the coin is biased if it comes up Heads and then tails?
I did .5(9/100)/.5(9/100+1/4)
which is: odds of it being biased * (odds of it being heads if it is biased * odds of it being tails if it is biased)
over
(odds of it being biased) * (odds of it being heads if it is biased * odds of it being tails if it is biased) * odds of it being fair * (odds of it being heads if its fair * odds of it being tails if it is fair)
with some algebra i get: 1/(1 + 25/9) which sounds about right i guess
I think the bayes one is wrong because you multiply the odds of the biased coin producing heads then tails with the odds of the unbiased coin producing heads then tails when you should be adding them together.
I get (0.5 * 0.09)/((0.5 * 0.9 * 0.1)+(0.5 * 0.5 * 0.5)) = 0.2647
I might be wrong too though
EDIT : nvm it is correct. The explanation is wrong and that confused me but the result / calculations are good
|
Could any of you suggest some good online math courses? I'm seriously considering returning to uni to get a degree in maths but I haven't really touched any of that in like 10 years so the term "rusty" doesn't even begin to cover my situation...
Some entry-level uni stuff would be great, something to help me recall knowledge from high school and beyond without overwhelming me entirely right off the bat (I used to be pretty good with algebra, analysis and statistics at uni, but it was long, long ago).
|
Khan Academy is excellent.
|
There are some good ones on youtube, depending on the courses you want.
MIT open courseware will be good for most courses.
Entry level uni stuff you either want calc 1 or you want pre-calc which is like basic functions, graphing, intro trig and some other random stuff.
So i'd recommend khan academy precalculus. However if they go through sections without many problem sets (which is sometimes the case on khan academy), I'd recommend you look up problem sets to do if it's a trouble section for you.
|
I'll check out Khan Academy. Quickly skimmed through their course list and it seems like a right place to get back on highschool math (since stuff like differential calculus is highschool level here).
|
I'm doing a math course part-time at the moment so I can learn/remember some math. One of my teachers recommends http://www.mathtutor.ac.uk/ , but I've not used it much. I rely more on Khan Academy youtube videos.
|
On April 18 2017 16:51 Manit0u wrote:Show nested quote +On April 17 2017 07:07 dsyxelic wrote:On April 17 2017 03:35 Manit0u wrote:On April 17 2017 03:17 dsyxelic wrote:
Question about android studio: how good of a computer do you or should you have to not have it lag? Did some android projects for a class and almost everybody reported it was extremely laggy besides like mac users. Id want to do more android work but I just cant deal with the lag on my machine and the specs arent that bad... I even used a separate emulator (genymotion) and other settings tricks off google to minimize lag to no avail. It's a matter of settings for the jetbrains products most of the time. You should set your caches etc. to reasonable levels so the indexing and garbage collection don't take as much time. Another trick I've learned in their products (which are awesome) is checking the "display memory usage" or somesuch option in the menu. Then you get this small bar in the bottom right that shows how much of the allowed memory your IDE is currently using and you can click on it to trigger immediate garbage collection (which drops it down from 1GB to 100MB instantly for example). I'll post the correct settings on tuesday, when I'm back at my workstation. Ah thanks, hopefully that saves my lag. And yes I agree the IDE itself is great, just the darn lag Ok, here goes. You can access it via Help -> Edit Custom VM Options... (or Edit Custom Properties)
-Xms2048m
-Xmx2048m
-XX:MaxPermSize=1024m
-XX:ReservedCodeCacheSize=240m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-ea
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-XX:+HeapDumpOnOutOfMemoryError
-XX:-OmitStackTraceInFastThrow
-Dawt.useSystemAAFontSettings=lcd
-Dsun.java2d.renderer=sun.java2d.marlin.MarlinRenderingEngine
You can tinker around with it. I've heard people had different results with different memory settings (sometimes lower is somehow better for compilation time etc. and I don't really know why).
holy moly as soon as I put that in I felt a noticeable difference in simple button clicks and switching between activities. I don't know how it did it but looks great.
thanks a lot, hopefully I won't have anymore lag issues. I definitely want to get another android project in now.
|
No problem. Glad I could help.
|
|
|
|
|
|
EPT
