On being able to play with a topic

I’ve always felt like I don’t have a decent grasp on a topic until I can “play” with it. For example, I have lots of fun asking questions in elementary real analysis, and to some extent topology and linear algebra, which usually leads to nice problems and more fun questions.

But with certain topics, like complex analysis, abstract algebra, and basically anything at the grad level, I can’t play with them. I don’t know how to come up with interesting questions to ask, and I can’t create any problems. I can understand definitions on a surface level, and solve textbook exercises somewhat fluently, but I still don’t feel like I have enough intuitive understanding to play with the topic.

So, some questions:

1) Usually the best way to really get to know a subject is to play with it, but how do you get good enough to play when you can’t play yet?

2) Does anyone else share this view on playing? Are there also topics for you that you feel comfortable playing with, and some where you just feel stuck?

submitted by /u/WaltWhit3
[link] [comments]

SPSS SYNTAX for A’ (A-prime)

I am conducting a test with signal detection theory (‘old’/’knew’ & ‘same’/different’), and have the Syntax and results for Hit rates, correct rejections, adjusted HR, adjusted False alarms (too ensure d’ does not sum to infinity) and also Bias (c). However, some of my data is skewed (negatively) and have found that d’ is not appropriate for this, and should use A’ instead.

When I have looked at articles with A’, I managed to find this:

COMPUTE APRIME = .5 + (ABS(HR – FA)/(HR – FA))*((HR – FA)**2 + ABS(HR – FA)) / (4*MAX(HR,FA) – 4*HR*FA).


(Stanislaw & Todorov, 1999)

However, when I input this into SPSS with my own variable names some of the functions do not come up in red (i.e., the second ABS – the first one does appear red). Note: I am fairly new to SPSS Syntax, but I understand that bright red means an error somewhere.

My question is therefore:

Will it matter in computing my data if the functions (i.e., ABS, MAX etc.) are not coloured red? Will the SYNTAX ignore them or include them?

Thank you all in advance, feel free to ask if I have not explained anything properly or have any questions.

submitted by /u/Commander_Nayr
[link] [comments]

Is a 14-hour drive manageable?

I’m considering driving from Georgia to Philadelphia to visit some family. It’s about a 900 mile trip and I’d be driving alone. The most I’ve ever driven in one sitting is about 8 hours and I was bored out of my mind near the end of it. I’d also be staying a week or so in Philly and then heading back to Georgia, so I’d be making the trip twice.

Does anyone have any experience with driving long distances? Any advice or stories would be helpful.

submitted by /u/Olaaaf
[link] [comments]

Strategies to reduce salt damage?

As long as I’ve lived in the Midwest I’ve had a beater to drive from Halloween to Easter to keep the salt off my nicer cars and just in case some moron slides into me. However I’m getting tired of trying to maintain a fleet of cars with my “summer daily”, winter beater, tow van (that I refuse to drive more than necessary), and project vehicles. So I’m thinking about selling the beater and making my S12 winter ready.

Ideas on how to keep this rice paper car from rusting out? POR-15 the whole underside?

submitted by /u/Sponsoredmiatadriver
[link] [comments]

PyCM 1.7 released: Machine learning library for confusion matrix statistical analysis


Changelog :

  • Gini Index (GI) added
  • Example-7 added
  • pycm_profile.py added
  • class_name argument added to stat,save_stat,save_csv and save_html methods
  • overall_param and class_param arguments empty list bug fixed
  • matrix_params_calc, matrix_params_from_table and vector_filter functions optimized
  • overall_MCC_calc, CEN_misclassification_calc and convex_combination functions optimized
  • Document modified

submitted by /u/sepandhaghighi
[link] [comments]

Need some affordable CD players for car recs gift for my bf

Hey guys. I’m clueless about cars but I am looking for something for my bf for Xmas. He is a music enthusiast and he just sold his 2008 BMW 3 series for a brand new 2018 Honda Civic. However, he’s a bit upset that the Honda does not have a CD player, he likes to buy CD to support bands. Are there anyways for him to play the CD in the car? Like a Bluetooth CD player or aux cord? I think that would be the perfect gift for him for Xmas

submitted by /u/bluecowboyboots2
[link] [comments]