Estimation/BitsAndBytes - Revision history

Admin: /* How many strings with a specified length of 140 characters are in 10 terabytes? */

2017-05-29T07:24:43Z

How many strings with a specified length of 140 characters are in 10 terabytes?

← Older revision		Revision as of 07:24, 29 May 2017
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	<math>		<math>
	10 Terabytes \times \dfrac{10^{12} Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{10^3 Bytes} \sim		10 Terabytes \times \dfrac{10^{12} Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{10^3 Bytes} \sim 10^{10}
	</math>		</math>

			That would be 10 billion tweets per day... Several orders of magnitude too high. A useful analysis nonetheless.

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	{{AlgorithmComplexityFlag}}		{{AlgorithmComplexityFlag}}

2017-05-29T07:23:34Z

How many strings with a specified length of 140 characters are in 10 terabytes?

← Older revision		Revision as of 07:23, 29 May 2017
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	<math>		<math>
	10 Terabytes \times \dfrac{10^{12} Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{~~1000~~ Bytes} \sim		10 Terabytes \times \dfrac{10^{12} Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{10^3 Bytes} \sim
	</math>		</math>

2017-05-29T07:23:14Z

How many strings with a specified length of 140 characters are in 10 terabytes?

← Older revision		Revision as of 07:23, 29 May 2017
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	<math>		<math>
	10 Terabytes \times \dfrac{10^12 Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{1000 Bytes} \sim		10 Terabytes \times \dfrac{10^{12} Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{1000 Bytes} \sim
	</math>		</math>

2017-05-29T07:23:02Z

How many strings with a specified length of 140 characters are in 10 terabytes?

← Older revision		Revision as of 07:23, 29 May 2017
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	<math>		<math>
	256 \text{unicode characters} \times \dfrac{2 \text{bytes}}{\text{unicode character}} = 512 bytes		256 \text{unicode characters} \times \dfrac{2 \text{bytes}}{\text{unicode character}} = 512 \text{bytes}
			</math>

			Maybe we're generous and allocate a whole 1000 bytes, to make it 1 KB, per tweet.

			Then 10 TB is equivalent to:

			<math>
			10 Terabytes \times \dfrac{10^12 Bytes}{1 Terabytes} \times \dfrac{1 Tweet}{1000 Bytes} \sim
	</math>		</math>

2017-05-29T07:20:34Z

How many strings with a specified length of 140 characters are in 10 terabytes?

← Older revision		Revision as of 07:20, 29 May 2017
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	<math>		<math>
	256 \text{unicode characters} \times \dfrac{16 \text{~~bits~~}}{\text{unicode character}}		256 \text{unicode characters} \times \dfrac{2 \text{bytes}}{\text{unicode character}} = 512 bytes
	</math>		</math>

2017-05-29T07:19:20Z

How many binary search function calls does it take to find one person in the million-person Manhattan phone book

← Older revision		Revision as of 07:19, 29 May 2017
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	</pre>		</pre>

	==How many binary search function calls does it take to find one person in the million-person Manhattan phone book==		==Examples==

			===How many binary search function calls does it take to find one person in the million-person Manhattan phone book===

	The above lookup table can be used to answer this question.		The above lookup table can be used to answer this question.
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	<math>		<math>
	\log_{2}(1,000,000) \sim log_{2}( 2^{20} ) \sim 20		\log_{2}(1,000,000) \sim log_{2}( 2^{20} ) \sim 20
			</math>

			===How many strings with a specified length of 140 characters are in 10 terabytes?===

			Rumor has it Twitter generates around 10 TB a day. How many 140 character strings would that be, in Python?

			Using compact arrays (which Strings are, by default), storing characters as unicode (16 bits, or 2 bytes, per character).

			Taking the overly simplistic view that there is around another 100 characters attached with each tweet to indicate username, dates, etc., would make each string:

			<math>
			256 \text{unicode characters} \times \dfrac{16 \text{bits}}{\text{unicode character}}
	</math>		</math>

2017-05-29T07:14:41Z

Estimating Bits and Bytes

@@ Line 16: / Line 16: @@
 [exbi] 2^60 =    1152921504606846976 ~ 1000^6
 </pre>
 =Flags=
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2017-05-29T07:12:16Z

Estimating Bits and Bytes

2017-05-29T07:12:06Z

Estimating Bits and Bytes

2017-05-29T07:11:56Z

Estimating Bits and Bytes

@@ Line 3: / Line 3: @@
 Via [https://www.youtube.com/watch?v=EKWGGDXe5MA Richard Feynman's Computing Heuristics lecture on Youtube]
-the following extremely useful relation, specified in [https://en.wikipedia.org/wiki/IEEE_1541-2002 IEEE 1541-2002]
+The following extremely useful relation, specified in [https://en.wikipedia.org/wiki/IEEE_1541-2002 IEEE 1541-2002]
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