Trouble mapping a function to an array; what is wrong?

[kulpojke]

I am trying to map a function to the contents of an array using the map() function. However, whenever the following function is called an error message is returned complaining that:

... line 121, in b_maker
b[k] = map(function,b[k])
TypeError: 'matrix' object is not callable

This is on a windows32 system, using python 2.5 with the numpy library.
In the following code data is a nested list of type float, target is a list of type float and function is a pre-defined function. In the first call to b_maker, where the problem occurs, function simply returns zero. I am confused because there are no matrix objects involved until after the line where the error is.

def b_maker(data,target,function):   
  b = ones((len(data)+1,1),float)                       
  for m in range(len(data)):                              
    b[m] = sqrt((data[m][0] - target[0])**2 + (data[m][1] - target[1])**2)  
  for k in range(len(b)-1):
    b[k] = map(function,b[k])   ##### <--Problem is here 
  b = array(b)
  b = matrix(b)
  b = b.T
  return b

I get the same error form this function:

def A_inverse(data,function):   
  A = zeros((len(data),len(data)+1),float)
  for m in range(len(data)):                              
    for n in range(len(data)):                          
      A[m,n] = distance_in_data(data,m,n)                 
  for k in range(len(A)):
    A[k] = map(function,A[k])     ## <----Problem occurs here
    A[k][k] =0.0
  for k in range(len(A)):
    A[len(A)-1][k] = 1.0
  A[len(A)-1][len(A)] = 0.0
  A = array(A)
  A = matrix(A)
  A = A.I
  return A

However the latter function is called and executes successfully many times before getting hung up and returning the error. I checked the data carefully to make sure there is not an invalid entry causing the problems, and all the functions being passed as the parameter function are fine. I am baffled.

This is semi-urgent because it is part of a project that must be finished in three days. Thank you

[bartonc]

I don't see why you are calling map() in a loop. map() goes through the iterable and returns an iterable with each element passed to and return from func:

>>> def func1(data):
... return data + 1
...
>>> aList = [1,2,3,4]
>>> map(func1, aList)
[2, 3, 4, 5]
>>>

[kulpojke]

That was a good point, and i have changed the code so that the loop is no longer included, but i still get the same error.

now then code looks like:

def b_maker(data,target,function):   
  b = ones((len(data)+1,1),float)                        
  for m in range(len(data)):                              
    b[m] = sqrt((data[m][0] - target[0])**2 + (data[m][1] - target[1])**2)                                               
  b = map(function,b)                             
  b = array(b)                                           
  b = matrix(b)                                          
  b = b.T                                                
  return b

but again, the error persists

[ghostdog74]

how did you call these 2 functions. show the whole script.

[kulpojke]

here it is:

def main(file_name):
  global i, max_lag, max_var, min_var, semivariogramz, w 
  w = [0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1]
  f = open(file_name,'r')
  data = tabfile_to_listnest(f)                                 # returns nested list
  f.close
  semivariogramz = semivar(data)                         # returns nested list
  i = len(semivariogramz) - 1
  max_lag = semivariogramz[i][0]
  max_var = semivariogramz[i][1]
  min_var = semivariogramz[0][1]
  F = [f0,f1,f2,f3,f4,f5,f6,f7,f8,f9]                            # f0...f9 defined elsewhere
  A_list = b_list = F
  for m in range(len(data)):
    target = data[m]
    
    for n in range(10):
      A_list[n] = A_maker(data,F[n])
      b_list[n] = b_maker(data,target,F[n])



def A_maker(data,function):  
  A = zeros((len(data),len(data)+1),float)               
  for m in range(len(data)):                             
    for n in range(len(data)):                            
      A[m,n] = distance_in_data(data,m,n)                 
  A = map(function,A)
  for k in range(len(A)):
    A[k][k] = 0.0
  for k in range(len(A)):
    A[len(A)-1][k] = 1.0
  A[len(A)-1][len(A)] = 0.0
  A = array(A)
  A = matrix(A)
  return A


def b_maker(data,target,function):  
  b = ones((len(data)+1,1),float)                         
  for m in range(len(data)):                              
    b[m] = sqrt((data[m][0] - target[0])**2 + (data[m][1] - target[1])**2)                
                                                          
  b = map(function,b)                                     
  b = array(b)                                           
  b = matrix(b)                                                                                        
  return b

[ghostdog74]

here it is:

def main(file_name):
  global i, max_lag, max_var, min_var, semivariogramz, w 
  w = [0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1]
  f = open(file_name,'r')
  data = tabfile_to_listnest(f)                                 # returns nested list
  f.close
  semivariogramz = semivar(data)                         # returns nested list
  i = len(semivariogramz) - 1
  max_lag = semivariogramz[i][0]
  max_var = semivariogramz[i][1]
  min_var = semivariogramz[0][1]
  F = [f0,f1,f2,f3,f4,f5,f6,f7,f8,f9]                            # f0...f9 defined elsewhere
  A_list = b_list = F
  for m in range(len(data)):
    target = data[m]
    
    for n in range(10):
      A_list[n] = A_maker(data,F[n])
      b_list[n] = b_maker(data,target,F[n])



def A_maker(data,function):  
  A = zeros((len(data),len(data)+1),float)               
  for m in range(len(data)):                             
    for n in range(len(data)):                            
      A[m,n] = distance_in_data(data,m,n)                 
  A = map(function,A)
  for k in range(len(A)):
    A[k][k] = 0.0
  for k in range(len(A)):
    A[len(A)-1][k] = 1.0
  A[len(A)-1][len(A)] = 0.0
  A = array(A)
  A = matrix(A)
  return A


def b_maker(data,target,function):  
  b = ones((len(data)+1,1),float)                         
  for m in range(len(data)):                              
    b[m] = sqrt((data[m][0] - target[0])**2 + (data[m][1] - target[1])**2)                
                                                          
  b = map(function,b)                                     
  b = array(b)                                           
  b = matrix(b)                                                                                        
  return b

this

 A_list[n] = A_maker(data,F[n])

is the problem. you are passing in a list F[n] to map() as the first argument which should be a function.
[/code]

[kulpojke]

this

 A_list[n] = A_maker(data,F[n])

is the problem. you are passing in a list F[n] to map() as the first argument which should be a function.
[/code]

But F[] is a list of functions. f0...f9 are defined elsewhere and F looks like:

F = [f0,f1,f2,f3,f4,f5,f6,f7,f8,f9]

[ghostdog74]

But F[] is a list of functions. f0...f9 are defined elsewhere and F looks like:

F = [f0,f1,f2,f3,f4,f5,f6,f7,f8,f9]

if its a list of functions, then you have to call map on each of them individually. use a for loop to go through every item in this list and pass to A_maker