Python Programming for Biology: Bioinformatics and Beyond

2

http://www.scipy.org/

.

3

 The  core  linear  algebra  part  of  LAPACK  is  called  BLAS.  For  some  operations  it  is

important  to  have  a  very  efficient  implementation  of  BLAS,  such  as  is  provided  by

ATLAS (

http://www.math-atlas.sourceforge.net

).

4

It follows that you can find the product of matrices that have different overall sizes, but

only if the size of the rows in the first is the same as the size of the columns of the second.

5

Mathematically we would have:

.

6

Make an error object.

7

The data type is ndarray in NumPy documentation.

8

The function name derives from the dot product operation commonly applied to vectors.

9

See link at

http://www.cambridge.org/pythonforbiology

.

10

This is assuming that the rotation follows the convention known as the right-hand rule.

11

Generating a vector at right angles to both of the vectors operated on.

12

This is also known as dihedral angle.

13

By convention this direction is right-handed; if you consider a typical graph, with the x

axis  going  across  the  bottom  and  the  y  axis  going  up  on  the  left  side,  then  the  cross-

product  will  come  out  of  the  page.  The  length  of  the  cross-product  is  also  important

because it depends on the sine of the angle between the two directions.

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