#### Basic Setup

```
from numpy import *
```

To import all numpy functions

### Variables

#### Declaration

```
#Declare a Pynum array with 10 elements
a = arange(1-10)
#Initialize it immediatly
a = ([1,2,3])
#Initialize it as explicit float
a = array([9,6,5,1],dtype=float)
#Or do the same with arange
a = arange(1-5,dtype=float)
```

#### Selection

```
#print out the second element
a[2]
#print out element 1 to 3, excluding the last
a[1:3]
```

### Matrix

#### Creation

```
#Creates a 4 x 4 identity matrix
a = eye(4)
#To create a matrix filled with ones use
a = ones(3,4)
#Maps a to the diagonal line of a matrix
b = diag(a)
```

#### Operations

```
#Scalar Product
b=dot(a,a)
#Outer Product
b=outer(a,a)
```

#### Selection

```
#choose the whole column from a in row 1
s2 = a[:,1]
#To explicitly set a value
a[2,3] = 5
```

### Properties

```
#Shows the type of a
type(a)
#Shows the length of a
a.shape
```

### Additional Information

```
# "#" is used for comments
# Potency is realized with **
a = 4 ** 2
# Intendation is used for scoping
for i in range(1,5):
print i
#functions are defined like this
def square(x):
y = x * x
return y
print quadrat(5)
```