function « numpy « Python Data Type Q&A

1. Python: Numpy array help. Is there a function to return the index of something in an array?    stackoverflow.com

I know there is a method for python list to return the first index of something

l = list(1,2,3)
l.index(2)
>>>  1

2. How can I create a numpy array holding values of a multi-variable function?    stackoverflow.com

I want to create an array holding a function f(x,y,z). If it were a function of one variable I'd do, for instance:

sinx = numpy.sin(numpy.linspace(-5,5,100))

3. Mapping functions of 2D numpy arrays    stackoverflow.com

I have a function foo that takes a NxM numpy array as an argument and returns a scalar value. I have a AxNxM numpy array data, over which I'd like ...

4. Mapping function to numpy array, varying a parameter    stackoverflow.com

First, let me show you the codez:

a = array([...])
for n in range(10000):
    func_curry = functools.partial(func, y=n)
    result = array(map(func_curry, a))
    do_something_else(result)
  ...

5. How can I build a polynomial lambda function from an list of coefficients?    stackoverflow.com

I have an list of coefficients that correspond to a polynomial expression, ie: [1,2,0] corresponds to x^2 + 2x + 0. I would like to put an arbitrary length array of ...

6. Broadcasting a python function on to numpy arrays    stackoverflow.com

Let's say we have a particularly simple function like

import scipy as sp
def func(x, y):
   return x + y

7. Passing Numpy arrays to a C function for input and output    stackoverflow.com

Oh my word I'm a fool. I was simply omitting the second and third arguments when calling the function. Like a fool. Because that's what I am. Original silly question follows: This seems like it must ...

8. A numpy.arange style function with array inputs    stackoverflow.com

I have numpy arrays of start indices and end indices from which I'd like to construct a flattened array of ranges. e.g. with inputs

s = np.array([1,2,3])
e = np.array([4,5,10])

array([1,2,3,2,3,4,3,4,5,6,7,8,9])

9. NumPy: Apply an index selecting function to multiple axes    stackoverflow.com

I'm writing code to optimize quantities that depend on a variable number of parameters. For the optimization I would like to apply index selecting functions such as numpy.argmax and numpy.argmin ...

10. Minimizing python function that has numpy array as argument    stackoverflow.com

I'm new to python, and I have the following problem: I am trying to minimize a python function that has a numpy array as one of its arguments. When I use ...

11. "If" function used for array in Python    stackoverflow.com

I have this function:

def q(x,y):
    r2 = (x/2.)**2 + (2.0*y)**2
    if (r2 > 0.04): 
        return 0.
  ...

12. Writing functions that accept both 1-D and 2-D numpy arrays?    stackoverflow.com

My understanding is that 1-D arrays in numpy can be interpreted as either a column-oriented vector or a row-oriented vector. For instance, a 1-D array with shape (8,) can be ...

13. How to "reduce" a numpy array using a costum binary function    bytes.com

I know there must be a simple method to do this. I have implemented this function for calculating a checksum based on a ones complement addition: def complement_ones_checksum(ints): """ Returns a complements one checksum based on a specified numpy.array of dtype=uint16 """ result = 0x0 for i in ints: result += i result = (result + (result >16)) & 0xFFFF return ...