#
# Polt Sine Wave...
#

#
# Replace a character in-place...
#
# s = 'foobar'
# s = s[:3] + 'x' + s[4:]	# replace the 3rd char with 'x'
# print s

import math as m

y_0 = 20
y_scale = 10

x_resolution = 10
deltaAngle = m.pi/x_resolution

x_ticks = 41
x_step = 1

#
# Plot (1) - Sine
#
hbar = '-' * y_0 + '+' + '-' * y_0
# print '-' * y_0, '+', '-' * y_0
print hbar
for x in range(0,x_ticks,x_step):
    bar = ' ' * 2 * y_0

    sin = m.sin(deltaAngle * x)
    y = int(sin * y_scale)	# # y = sin * y_scale
    bar = bar[:y_0+y]+'s'+bar[y_0+y+1:]

#    cos = m.cos(deltaAngle * x)
#    y = int(cos * y_scale)	# # y = sin * y_scale
#    bar = bar[:y_0+y]+'c'+bar[y_0+y+1:]

    bar = bar[:y_0+0]+'|'+bar[y_0+0+1:]
    print bar

#
# Plot (2) - Cosine
#
hbar = '-' * y_0 + '+' + '-' * y_0
# print '-' * y_0, '+', '-' * y_0
print hbar
for x in range(0,x_ticks,x_step):
    bar = ' ' * 2 * y_0

#    sin = m.sin(deltaAngle * x)
#    y = int(sin * y_scale)	# # y = sin * y_scale
#    bar = bar[:y_0+y]+'s'+bar[y_0+y+1:]

    cos = m.cos(deltaAngle * x)
    y = int(cos * y_scale)	# # y = sin * y_scale
    bar = bar[:y_0+y]+'c'+bar[y_0+y+1:]

    bar = bar[:y_0+0]+'|'+bar[y_0+0+1:]
    print bar

#
# Plot (3) - Sin + Cos
#
hbar = '-' * y_0 + '+' + '-' * y_0
# print '-' * y_0, '+', '-' * y_0
print hbar
for x in range(0,x_ticks,x_step):
    bar = ' ' * 2 * y_0

    sin = m.sin(deltaAngle * x)
    y = int(sin * y_scale)	# # y = sin * y_scale
    bar = bar[:y_0+y]+'s'+bar[y_0+y+1:]

    cos = m.cos(deltaAngle * x)
    y = int(cos * y_scale)	# # y = sin * y_scale
    bar = bar[:y_0+y]+'c'+bar[y_0+y+1:]

    bar = bar[:y_0+0]+'|'+bar[y_0+0+1:]
    print bar

#
# Plot (4) - Sine
#
print '-' * y_0, '+', '-' * y_0
for x in range(0,x_ticks,x_step):
    sin = m.sin(deltaAngle * x)
    y = int(sin * y_scale)	# # y = sin * y_scale

    #+ print ' ' * y_0, '*' * (y+y_0)
    #+ print ' ' * (y+y_0), '$'
    #+ print "sin(",x,"/",x_resolution," pi) =", sin, y

    if ( y > 0 ):
	print ' ' * y_0, '|', ' ' * (y-1), '@'
    elif y == 0:
	print ' ' * y_0, ':'
    else:
	print ' ' * (y_0+y-2), '@', ' ' * (-y-1), '|'

print
#
# Plot (5) - Sine
#
print '-' * y_0, '+', '-' * y_0
for x in range(0,x_ticks,x_step):
    sin = m.sin(deltaAngle * x)
    y = int(sin * y_scale)	# # y = sin * y_scale
    if ( y > 0 ):
	print ' ' * y_0, '|', '@' * y
    else:
	print ' ' * (y_0+y-1), '@' * (-y), '|'

# y_axis = "                         "
    # y_axis[y] = '*'	# CANNOT change string member
    # print y_axis

#
# Using 2D scan lines -- Example
#
'''
matrix = [ '0' * 10, '1' * 10, '2' * 10 ]
matrix[0]=matrix[0][:3]+'x'+matrix[0][4:]
matrix[1]=matrix[1][:4]+'y'+matrix[1][5:]
matrix[2]=matrix[2][:5]+'z'+matrix[2][6:]
print ('%s\n%s\n%s\n' % (matrix[0], matrix[1], matrix[2]))
'''

matrix = []
n_cols = 80
#
# create blank screen
#
for y in range(y_0*2+1):
    matrix.append(' ' * n_cols)
    row_id = len(matrix)-1
    #+ print ('%2d: %s' % (row_id, matrix[row_id-1]))

#
# create centeral line
#
matrix[y_0]= '-' * n_cols

#
# create function curves
#
for x in range(0,x_ticks,x_step):

    sin = m.sin(deltaAngle * x)
    y = int(sin * y_scale)	# # y = sin * y_scale
    y += y_0			# shift up

    matrix[y]=matrix[y][:x]+'S'+matrix[y][x+1:]

    cos = m.cos(deltaAngle * x)
    y = int(cos * y_scale)	# # y = sin * y_scale
    y += y_0

    matrix[y]=matrix[y][:x]+'c'+matrix[y][x+1:]

n_rows = len(matrix)
print 'n_rows =', n_rows
for y in range(n_rows-1,-1,-1):
    print ('%2d: %s' % (y, matrix[y]))
    #- print ('%2d: %s' % (y, 'xxx'))

print 'n_rows =', n_rows, '(reversed)'
for y in range(n_rows):
    print ('%2d: %s' % (y, matrix[y]))
    

#
# Using Array module
#

'''
import array as arr
a = arr.array('d', [1.1, 3.5, 4.5])
print(a)
print(a[0])
print(a[1])
print(a[2])
'''