Difference between revisions of "CompSciWeek13"
From Predictive Chemistry
(→Numerical Integration) |
(→Numerical Integration) |
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* Working with machines: binary |
* Working with machines: binary |
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** inspecting binary formats with od |
** inspecting binary formats with od |
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| + | Example: [http://man7.org/linux/man-pages/man5/elf.5.html ELF] header |
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| + | |||
| + | od -t x1 -t c -N 8 /bin/bash |
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| + | |||
| + | Binary comes in lots of units |
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| + | |||
| + | 8 bits = 1 byte |
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| + | 4 bits = 1 nibble |
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| + | 1 byte = 1 ascii character |
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| + | 2 bytes = 1 short |
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| + | 4 bytes = 1 32-bit int = 1 float |
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| + | 8 bytes = 1 64-bit int = 1 64-bit address = 1 double = 1 float complex |
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| + | 16 bytes = 1 long double = 1 double complex |
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| + | |||
| + | Byte ordering on most modern 64-bit processors is little-endian (Intel, AMD) |
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| + | |||
| + | in base 10, this would mean the 4-digit representation of the number 123 is |
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| + | |||
| + | 3 = 0011 |
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| + | 2 = 0010 |
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| + | 1 = 0001 |
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| + | 0 = 0000 |
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| + | |||
| + | The binary together would read: |
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| + | |||
| + | 0011 0010 0001 0000 |
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| + | |||
| + | Since we have to use 4 digits, but the little end (least significant byte) goes first. |
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= Basis Functions = |
= Basis Functions = |
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Revision as of 12:27, 17 November 2014
Numerical Integration
- Van der Pol Oscillator: <math>\ddot u - \mu (1-u^2) \dot u + u = 0</math>
- Implementations in OpenOffice Spreadsheet, GNU ODE, and Python
- Perturbed initial conditions, Lyapunov exponents, and large deviation principles
- Working well with others: text
- Working with machines: binary
- inspecting binary formats with od
Example: ELF header
od -t x1 -t c -N 8 /bin/bash
Binary comes in lots of units
8 bits = 1 byte 4 bits = 1 nibble 1 byte = 1 ascii character 2 bytes = 1 short 4 bytes = 1 32-bit int = 1 float 8 bytes = 1 64-bit int = 1 64-bit address = 1 double = 1 float complex 16 bytes = 1 long double = 1 double complex
Byte ordering on most modern 64-bit processors is little-endian (Intel, AMD)
in base 10, this would mean the 4-digit representation of the number 123 is
3 = 0011 2 = 0010 1 = 0001 0 = 0000
The binary together would read:
0011 0010 0001 0000
Since we have to use 4 digits, but the little end (least significant byte) goes first.
Basis Functions
- Constructing B-splines - tensor method
- Representing the differentiation operator
- Solving PDEs using the implicit method
