#! /usr/bin/env python3
#
def python02 ( ):

#*****************************************************************************80
#
## python02() carries out exercises for the python02 lab.
#
#  Modified:
#
#    05 May 2022
#
  import numpy as np

  print ( '' )
  print ( 'python02():' )
  print ( '  Exercises for python02 lab.' )
#
#  Demonstrate the use of numpy.
#
  x = np.sqrt ( 20.0 )
  print ( '' )
  print ( '  numpy.sqrt ( 20.0 ) = ', x )
#
#  Read the data.
#
  data = np.loadtxt ( fname = 'inflammation-01.csv', delimiter = ',' )
  print ( '' )
  print ( '  Data read from file:' )
  print ( data )

  print ( '' )
  print ( '  type(data) = ', type ( data ) )
  print ( '  data.dtype = ', data.dtype )
  print ( '  data.shape = ', data.shape )
#
#  Access individual items.
#
  print ( '  First entry is  ', data[0,0] )
  print ( '  Middle entry is ', data[30,30] )
  print ( '  Last entry is   ', data[59,39] )
#
#  Work with individual entries.
#
  print ( '  data[0,0] = ', data[0,0] )
  save = data[0,0]
  type ( data[0,0] )
  x = data[0,0] - 2.0 * data[0,1] + data[0,2]
  print ( '  x = data[0,0] - 2.0 * data[0,1] + data[0,2] = ', x )
  data[0,0] = 1.0
  print ( '  data[0,0] = ', data[0,0] )
  data[0,0] = save     #  Restore the original value.
#
#  Print row 17
#
  print ( data[17,:] )
#
#  Print column 25
#
  print ( data[:,25] )
#
#  Print a subtable.
#
  print ( data[:3,36:] )
#
#  Statistics for entire table.
#
  maxval = np.max ( data )
  minval = np.min ( data )
  average = np.mean ( data )
  stdev = np.std ( data )

  print ( '' )
  print ( '  Statistics for entire table:' )
  print ( '  maximum = ', maxval )
  print ( '  minimum = ', minval )
  print ( '  average = ', average )
  print ( '  stdev =   ', stdev )
#
#  Statistics for patient 17
#
  maxvali17 = np.max ( data[17,:] )
  minvali17 = np.min ( data[17,:] )
  averagei17 = np.mean ( data[17,:] )
  stdevi17 = np.std ( data[17,:] )

  print ( '' )
  print ( '  Statistics for row i = 17' )
  print ( '  maximum = ', maxvali17 )
  print ( '  minimum = ', minvali17 )
  print ( '  average = ', averagei17 )
  print ( '  stdev =   ', stdevi17 )
#
#  Statistics for day 25
#
  maxvalj25 = np.max ( data[:,25] )
  minvalj25 = np.min ( data[:,25] )
  averagej25 = np.mean ( data[:,25] )
  stdevj25 = np.std ( data[:,25] )

  print ( '' )
  print ( '  Statistics for row j = 25' )
  print ( '  maximum = ', maxvalj25 )
  print ( '  minimum = ', minvalj25 )
  print ( '  average = ', averagej25 )
  print ( '  stdev =   ', stdevj25 )
#
#  Row and column measurements.
#
  meanrows = np.mean ( data, axis = 1 )
  print ( '' )
  print ( '  meanrows = np.mean ( data, axis = 1 )' )
  print ( '  meanrows = ', meanrows )
  print ( '  meanrows.shape = ', meanrows.shape )
  print ( '  meanrows[25] = ', meanrows[25] )

  maxcols = np.max ( data, axis = 0 )
  print ( '' )
  print ( '  maxcols = np.max ( data, axis = 0 )' )
  print ( '  maxcols = ', maxcols )
  print ( '  maxcols.shape = ', maxcols.shape )
  print ( '  maxcols[17] = ', maxcols[17] )
#
#  String indexing
#
  s1 = 'breakfast'
  print ( '' )
  print ( '  s1 = ', s1 )
  print ( '  s1[0] = ', s1[0] )
  print ( '  s1[0:0] = ', s1[0:0] )  # Surprise!
  print ( '  s1[0:2] = ', s1[0:2] )
#
#  Indexing tricks.
#
  s1 = 'breakfast'
  s2 = 'lunch'
  print ( '' )
  print ( '  s1 = ', s1 )
  print ( '  s2 = ', s2 )
  print ( '  s2[1:] = ', s2[1:] )
  print ( '  s1[:2] + s2[1:] = ', s1[:2] + s2[1:] )
  print ( '  s1[5:-1] = ', s1[5:-1] )
#
#  Write one expression that gets last three characters of any string.
#
  a = -3
  b = -1
  s = 'buffalo'
  print ( '  s[',a,':',b,'] = ', s[a:b] )
  s = 'bugblatter beast of traal'
  print ( '  s[',a,':',b,'] = ', s[a:b] )
  s = 'me'
  print ( '  s[',a,':',b,'] = ', s[a:b] )

  s = 'buffalo'
  print ( '  s = ', s )
  print ( '  s[3:3] = ', s[3:3] )

  print ( '' )
  print ( '  data[3:3,4:4].shape = ', data[3:3,4:4].shape )
  print ( '  data[3:3,;].shape = ', data[3:3,:].shape )
#
#  Create arrays.
#
  rowvec = np.array ( [ 0, 1, 2 ] )
  print ( '' )
  print ( '  rowvec = ', rowvec )
  table = np.array ( [ [ 0, 1, 2 ], [ 10, 11, 12 ], [ 20, 21, 22 ] ] )
  print ( '  table = ', table )
  colvec = np.array ( [ [ 0 ], [ 10 ], [ 20 ] ] )
  print ( '  colvec = ', colvec )
#
#  Stacking.
#
  A = np.array ( [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] )
  print ( '' )
  print ( '  A = ', A )
  print ( '  np.hstack( [A,A] ) = ', np.hstack ( [ A, A ] ) )
  print ( '  np.vstack( [A,A] ) = ', np.vstack ( [ A, A ] ) )
#
#  Differences.
#
  sample = data[17,10:15]
  change = np.diff ( sample )
  print ( '' )
  print ( '  sample = ', sample )
  print ( '  np.diff ( sample ) = ', np.diff ( sample ) )

  changes = np.diff ( data )
  print ( '  np.diff(data) = ', np.diff ( data ) )
  return

if ( __name__ == "__main__" ):
  python02 ( )