update

Author: Andreas Kugel

src/1-basicData.py

@@ -5,12 +5,11 @@
 import sys
 import pygame
 import time
-import os
 import random
 from mpl_toolkits.mplot3d import Axes3D
 
 
-#playing and plotting data from a wave file
+# playing and plotting data from a wave file
 
 # pgame stuff related to playing sound
 pygame.mixer.pre_init(24000, size=-16, channels=1)
@@ -48,7 +47,7 @@
         signal = "dqpinfqfmmdqwpdqwpdqwodmopmodpwndeniqwqwnfojqnwd"
         print("Using ", signal)
 
-    txtSignal = signal # make a copy of the text        
+    txtSignal = signal # make a copy of the text
     signal = np.fromstring(signal.upper(), "uint8")
     sigMin = min(signal)
     signal -= min(signal)
@@ -67,7 +66,7 @@
                        break
     max3d = min(len(signal), min3d + 200 )
     print("min ",min3d,", max ",max3d)
-                   
+
 #x3d = [i for i in range(min3d,max3d)]
 #y3d = [signal[i] % 10 for i in range(min3d,max3d)]
 #z3d = [signal[i] % 100 for i in range(min3d,max3d)]
@@ -85,7 +84,7 @@
 
 for i in range(len(x3d)):
     ax.text(x3d[i],y3d[i],z3d[i], label3d[i], size=20)
-    
+
 plt.axis("off")
 plt.title('A pile of numbers ...')
 plt.get_current_fig_manager().full_screen_toggle()
@@ -106,7 +105,7 @@
 plt.figure()
 plt.title('Sequential numbers: A Wave display/timeseries...')
 plt.plot(signal)
-plt.get_current_fig_manager().full_screen_toggle() 
+plt.get_current_fig_manager().full_screen_toggle()
 plt.show()
 
 # we can also create a 2d plot in the following way
@@ -116,7 +115,7 @@
 signal2d = np.reshape(signal, (-1, int(ncols))) # reshape
 plt.imshow(signal2d) # create image
 plt.title('2D arranged numbers: An Image ...')
-plt.get_current_fig_manager().full_screen_toggle() 
+plt.get_current_fig_manager().full_screen_toggle()
 plt.show()
 
 # recalculate 3d PARMS
@@ -138,21 +137,21 @@
 ha.plot_surface(x,y, signal2d, color='b')
 
 plt.title('3D-stlye arranged numbers: A Surface Plot ...')
-plt.get_current_fig_manager().full_screen_toggle() 
+plt.get_current_fig_manager().full_screen_toggle()
 plt.show()
 
 
 ##### text display if not wav
 if not useWav:
     label3d = ["%c" % (signal[i]+sigMin)  for i in range(min3d,max3d)]
-    pntSize = 0 
+    pntSize = 0
     fig = plt.figure()
     ax = Axes3D(fig)
     ax.scatter(x3d,y3d,z3d, s= pntSize)
 
     for i in range(len(x3d)):
         ax.text(x3d[i],y3d[i],z3d[i], label3d[i], size=20)
-        
+
     plt.axis("off")
     plt.title('A pile of numbers with encoding: characters ...')
     plt.get_current_fig_manager().full_screen_toggle()
@@ -203,7 +202,7 @@
 sd = pygame.mixer.Sound(longSignal[:sl])
 sd.play()
 
-#important to wait until sound finished 
+#important to wait until sound finished
 while pygame.mixer.get_busy():
     pass
 
@@ -212,7 +211,7 @@
 
 ##########################################
 # initialize speech output
-#for windows speech, we need win32 stuff 
+#for windows speech, we need win32 stuff
 import platform
 if "windows" in platform.system().lower():
     import win32api
@@ -246,15 +245,15 @@
 plt.title('Ottos Mops hops ...')
 
 if not useWav:
-    tfig = plt.subplot(1,3,2) 
+    tfig = plt.subplot(1,3,2)
     tfig.axis("off")
     tfig.annotate(txtSignal,\
         xy=(1, 1), xytext=(.4,.8), xycoords="data", \
         textcoords="axes fraction",ha="left", va="top", size=14)
 
     import wordcloud
     wc = wordcloud.WordCloud().generate_from_text(txtSignal)
-    wfig = plt.subplot(1,3,3) 
+    wfig = plt.subplot(1,3,3)
     wfig.axis("off")
     wfig.imshow(wc)
 
@@ -276,5 +275,4 @@
     if i < len(lines):
         engine.say(lines[i])
         engine.runAndWait()
-    plt.pause(.1)        
-
+    plt.pause(.1)

src/2a-chessPrint.py

@@ -1,8 +1,83 @@
 """ Demonstrate fundamental programming elements
-by creating a checker board, 8 by 8 fields, 
+by creating a checker board, N by N fields,
 field size is configurable, same width and height
+
+The following programming constructs are demonstrated:
+
+Comment
+    # The "#" starts a comment until the end of the line
+    # We can write whatever we want
+
+Variable
+    Normally, we have to remember values sometime in order to perform
+    operations on or with them later on. A variable is an object which
+    has a name and a value, like so:
+    var1 = "some text"
+    or
+    var2 = 123
+    or
+    var3 = True
+    We can change the value of variables any time
+
+Constant
+    A constant is basically a variable were the value cannot be changed
+    (immutable). We don't have this here but we use some variables in this
+    style
+
+Operation
+    We have a large number of operator available to do math, logic and other
+    things like:
+        a = 5 + 3
+        b = a * 4
+        c = a % 3  # The is the modulo operation (reminder)
+        d = 5 == 6  # d is False. The double "=" means "has equal value"
+
+Branch
+    We test a condition and do one thing when it is true and another thing
+    when it is false using IF ... ELSE ... statements like:
+    if a == 4 then:
+        do thing 1
+    else:
+        do thing 2
+
+Iteration (loop)
+    We can repeat sections of the code several times in different ways, for
+    example for a (fixed) number of times using a
+    FOR LOOP like so:
+        for i in range(10):
+            statements ...
+    of while a condition is true like so:
+    while a < b:
+        statements ...
+
+Block
+    Every language has it's own syntax to form group of statements. Python
+    uses indentation. All statements in sequence with the same indent level
+    are in the same block, like so:
+    if a == 4 then:
+        thing1a()   # call function thing1a in the IF branch
+        thing1b()   # same identation => same block => do also thing1b
+    else:           # same indent as the "if", previous block terminated
+        thing2()    # new block, do thing2 in the ELSE branch
+    thing3()        # not indented, previous block terminated. Thing3 is
+                    # outside the IF-ELSE block
+
+Function
+    we use functions to execute code which is (re)used several times
+    we can provide parameters to the functions, so the same code can
+    actually perform (slightly) different depending on the parameters
+    Function can return "objects" (we don't know what exactly that is yet,
+    but in Python more or less everything is an object)
+    Functions have to be declared before we can use them like so:
+    def <name>([paramters]):
+        ... function code ...
+        [return]
+
 """
 
+########################################################################
+# this is our first function declaration
+# We have to decalre the function before we use it
 # function to make one linear segment of a pattern
 def segment(width, color):
     """ print <width> items of a color """
@@ -11,39 +86,39 @@ def segment(width, color):
         # print(color,end="") # simple verion
         print("{0:2d}".format(color),end="") # this looks better
 
-# the main function 
+########################################################################
+# our second function is the main function
 def main():
     """create a checker board pattern using a function"""
 
-    # constants
+    # constants (actually just variables we do not change any more)
     fields = 8
     fieldWidth = 4
-    
+
     # variables
     row = 0
     column = 0
     # set color to 0
     color = 0
+    # we iterate until we are done ...
     while row < fields*fieldWidth and column < fields*fieldWidth:
         # print segment
         segment(fieldWidth,color)
-        # invert color
+        # invert color after every segment
         color = 1 if color == 0 else 0
-        # increment column
+        # increment column. go back to 0 after 8 fields
         column = column + fieldWidth if column < fieldWidth*(fields-1) else 0
         # new line and increment row if column = 0
         if column == 0:
             print("") # prints a new line
-            # reset line
+            # next row
             row = row + 1
         # invert color again if new row and end of field
         if column == 0 and row % fieldWidth == 0 :
             color = 1 if color == 0 else 0
-        
 
+
+########################################################################
 # call the main function
 if __name__ == "__main__":
     main()
-    
-
-    

src/2b-chessList.py

@@ -1,27 +1,32 @@
 """ Demonstrate fundamental programming elements
-by creating a checker board, 8 by 8 fields, 
+by creating a checker board, 8 by 8 fields,
 field size is configurable, same width and height
+
+This is basically the same as in the previous example, but instead
+of printing the segment immediately we create a data structure
+based upon lists ([]) and append the segment to the line
+
 """
 
 # function to make one linear segment of a pattern
 def segment(width, color):
-    """ put <width> items of color in a row starting at position row,col (= y,x)"""
-    # initialize a new list as a numpy array
+    """ put <width> items of color in a row"""
+    # initialize a new list
     segment = []
     # add items with a FOR LOOP
     for i in range(width):
         segment.append(color)
     # return the list
     return segment
 
-# the main function 
+# the main function
 def main():
     """create a checker board pattern using a function"""
 
     # constants
     fields = 8
     fieldWidth = 2
-    
+
     # variables
     row = 0
     column = 0
@@ -38,25 +43,22 @@ def main():
         color = 1 if color == 0 else 0
         # increment column
         column = column + fieldWidth if column < fieldWidth*(fields-1) else 0
-        # add line to board and increment row if column = 0
+        # if column == 0 then previous line is complete.
+        # add line to board, increment row and start a new line
         if column == 0:
             board.append(line)
-            # reset line
-            line = []
             row = row + 1
+            line = []
         # invert color again if new row and end of field
         if column == 0 and row % fieldWidth == 0 :
             color = 1 if color == 0 else 0
-        
+
 
     print("Checker board")
     for b in board:
         print(b)
-    
+
 
 # call the main function
 if __name__ == "__main__":
     main()
-    
-
-    

src/2c-chessNp.py

@@ -1,30 +1,42 @@
 """ Demonstrate fundamental programming elements
-by creating a checker board, 8 by 8 fields, 
+by creating a checker board, 8 by 8 fields,
 field size is configurable, same width and height
+
+Again, the basic algorith is like before, but this time
+we use a more advanced data structure provided by a external library
+The library "numerical python" (numpy) is imported with the statement
+#import numpy as np
+and it's functions are called as "np.function_name()"
+
+We use the "array" data type to realize a 2D matrix, representing
+the checker board. The 2D matrix is similar to the list of lists but
+offers additional operations e.g. on the entire dataset which we use
+in the future
+
 """
 
 # numpy is a helper library
 import numpy as np
 
 # function to make one linear segment of a pattern
 def segment(width, color):
-    """ put <width> items of color in a row starting at position row,col (= y,x)"""
+    """ put <width> items of color in a row"""
     # initialize a new list as a numpy array
-    segment = np.empty(width) # 
+    segment = np.empty(width) #
     # add items with a FOR LOOP
     for i in range(width):
         segment[i] = color
     # return the list
     return segment
 
-# the main function 
+# the main function
 def main():
     """create a checker board pattern using a function"""
 
     # constants
     fields = 8
     fieldWidth = 2
-    
+
     # variables
     row = 0
     column = 0
@@ -44,15 +56,12 @@ def main():
         # invert color again if new row and end of field
         if column == 0 and row % fieldWidth == 0 :
             color = 1 if color == 0 else 0
-        
+
 
     print("Checker board")
     print(board)
-    
+
 
 # call the main function
 if __name__ == "__main__":
     main()
-    
-
-