%pylab inline

a=[1,2,3]
a=a+1

for k in range(3):
    a[k]=a[k]+1

from numpy import *
a=array([1,2,3,4,5,6])
print(a)

a=array([2.0,4.0,8.0,16.0])
b=array([0,1+0j,1+1j,2-2j])
c=array(['a','b','c','d'])
print(a)
print(b)
print(c)

output=[n for n in range(10)]
print(output)

output=[]
for n in range(10):
    output.append(n)
print(output)

array(output)

array([n for n in range(10)])

array([2.0*k**0.563 for k in range(0,10,2)])

zeros(5)

ones(10)

arange(5)

arange(0,10,2)

linspace(0,10,20) #makes an array of 20 points linearly spaced from 0 to 10

linspace(-5,5,15) #15 points in range from -5 to 5

array([1,2,3.14]) # [int,int,float] -> [float,float,float]

array([1.0,1+1j,'hello']) #array data is upcast to strings

array([1,2,3,4,5],dtype=float)

arange(2,10,2,dtype=complex)

array([k for k in range(10)],dtype=str)

a=array([1,2,3,4])
5.0*a #This gets upcasted because 5.0 is a float

5*a**2-4

x=linspace(-pi,pi,10)
sin(x)

x=array([x**2 for x in range(4)])
sqrt(x)

x=array([2*n+1 for n in range(10)])
sum(x) #sums up all elements in the array

a=array([0,-1,2,-3,4])
print(a<0)

a=arange(10)
print((mod(a,2)!=0))

a=arange(20)
a[3::3]

a[3::3]=-1
print(a)

a=arange(10)
a[::-1]

a=linspace(-10,10,20)
print(a[a<=-5])

print(a[-8<a<=-5])

N=20
# generate a list from 2->N
numbers = []
for i in range(2,N+1):                 # This can be replaced by array
    numbers.append(i)
# Run Seive of Eratosthenes algorithm marking nodes with -1
for j in range(N-1):
    if numbers[j]!=-1:
        p=numbers[j]
        for k in range(j+p,N-1,p):     # This can be replaced by array
            numbers[k]=-1
# Collect all elements not -1 (these are the primes)
primes = []
for i in range(N-1):                   # This can be replaced by array
    if numbers[i]!=-1:
        primes.append(numbers[i])
print(primes)

N=20
# generate a list from 2->N
numbers=arange(2,N+1)                 # replaced for-loop with call to arange
# Run Seive of Eratosthenes algorithm
# by marking nodes with -1
for j in range(N-1):
    if numbers[j]!=-1:
        p=numbers[j]
        numbers[j+p:N-1:p]=-1         # replaced for-loop by slicing array
# Collect all elements not -1 (these are the primes)
primes=numbers[numbers!=-1]           # Used conditional statement to get elements !=-1
print(primes)

from IPython.core.display import HTML
def css_styling():
    styles = open("styles/style.css", "r").read()
    return HTML(styles)
css_styling()