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WikiCards · Card list · Science cards · Principal component analysis
Rare card · Science
Principal component analysis, a Rare card
Principal component analysis is a linear dimensionality reduction technique with applications in exploratory data analysis, visualization and data preprocessing.
- Rarity
- Rare
- Domain
- Science
- ATK
- 88
- DEF
- 89
- Power
- 177
- Wikipedia reads a year
- 380,000
Power 177 (ATK + DEF): stronger than 90 % of WikiCards cards.
Principal component analysis quiz: 3 questions
Three questions on the Principal component analysis card, the way WikiCards duels ask them. Pick an answer, the facts are just below.
Find the missing word
Here, a best-fitting line is defined as one that minimizes the average squared ______ distance from the points to the line.
Answer
perpendicular. Here, a best-fitting line is defined as one that minimizes the average squared perpendicular distance from the points to the line. From the Principal component analysis article on Wikipedia.
Which of these cards hits hardest (highest ATK)?
Answer
Lithium-ion battery. Lithium-ion battery 92 · Principal component analysis 88 · Anxiety 85 · DVD 82 ATK in WikiCards.
In a duel, each round asks a question like these about the opposing card, with 15 seconds to answer.
The facts on the card
The card carries these facts from its Wikipedia article.
- The data are linearly transformed onto a new coordinate system such that the directions capturing the largest variation in the data can be easily identified.
- The principal components of a collection of points in a real coordinate space are a sequence of p unit vectors, where the i -th vector is the direction of a line that best fits the data while being orthogonal to the first i − 1 vectors.
- Here, a best-fitting line is defined as one that minimizes the average squared perpendicular distance from the points to the line.
Why it is Rare
Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Principal component analysis article was read about 380,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 88 and blocks with 89: each hit it takes is cut by 36 %.
How to get Principal component analysis
Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.
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The cards just above and just below Principal component analysis in the power ranking, all domains together.
- Arab–Israeli conflictRare · Society · ATK 87 DEF 90
- DubrovnikRare · Society · ATK 87 DEF 90
- Lithium-ion batteryRare · Science · ATK 92 DEF 85
- TianjinRare · Society · ATK 90 DEF 87
- CampaniaRare · Society · ATK 85 DEF 92
- Dirty WarRare · History · ATK 92 DEF 85
Card lists
- Wikipedia quizNew questions every day
- All cards from A to ZEvery card, by name
- Science cards
- Legendary cards
- Tier listS and A tiers by power (ATK + DEF)
Credits
Text : Wikipedia, Principal component analysis (revision), CC BY-SA 4.0. Photo : Nicoguaro, CC BY 4.0, Wikimedia Commons.
