Let a = np.arange(1, 4). To get the 2 dimensional multiplication table for a, I do: For 3 dimensions, I can do the following: How could I write a function that takes a numpy array a and a number of dimensions n as input and ouputs the n dimensional multiplication table for a? Answer This should do what you ne…
Tag: multidimensional-array
Accessing JSON Elements W/ Python
I want to access the individual data for ‘vin’, ‘make’, ‘year’, etc and export to a csv. I have tried accessing it by I get a KeyError: ‘year’ This is part of the JSON tree I am working with I am just a bit confused on the syntax as I have access data from a 2D …
Select a random element from a 2d array list in python
I currently have a 2d array generated by this code: If I want to select a random cell, how would I go about it? random.choice doesn’t seem to be working. Answer You could do something like If you do want to use random.choice, you’ll have to use it twice, as the first call will return an array of C…
Finding elements unique to each rows in a 2D array
Given a 2D Array (Python List), I need to find a new 1D such that it contains elements unique in each column. For example: should give me for example, [1,-1,0,3,4]. My trials so far: results is a 2D array of size 3 rows and n columns. last is the array which stores the end result, better said the unique value…
How to define a 2D array of (x,y) coordinates
I have a 2d space of (x,y) coordinates that I want to model in python and want to know a way to define the 2d space in python where I can assign multiple values to a point (x,y). Later values at coordinates will be changed based on some coordinate dependent calculations. I thought about using numpy array to c…
Python / numpy: Remove empty (zeroes) border of 3D array
I have a 3D numpy array. This can be thought of as an image (to be exact it’s values of field points). I want to remove the border (0 values, note that there are negative values possible) in all dimensions. The restriction is that the dimension remains the same for all molecules, eg. I only want to remo…
finding and replacing elements in a multidimensional list (python)
Similar to this question: finding and replacing elements in a list (python) but with a multi-dimensional array. For example, I want to replace all the N’s with 0’s: I want to change it to: Answer You can use a nested list comprehension: Output:
How can I get descriptive statistics of a NumPy array?
I use the following code to create a numpy-ndarray. The file has 9 columns. I explicitly type each column: Now I would like to get some descriptive statistics for each column (min, max, stdev, mean, median, etc.). Shouldn’t there be an easy way to do this? I tried this: but this returns an error: TypeEr…
Convert a numpy.ndarray to string(or bytes) and convert it back to numpy.ndarray
I’m having a little trouble here, I’m trying to convert a numpy.ndarray to string, I’ve already done that like this: It works, but I’m wondering if I can transform it back to a numpy.ndarray. What’s the best way to do this? I’m using numpy 1.8.1 Context: The objective is to…
Test if an array is broadcastable to a shape?
What is the best way to test whether an array can be broadcast to a given shape? The “pythonic” approach of trying doesn’t work for my case, because the intent is to have lazy evaluation of the operation. I’m asking how to implement is_broadcastable below: or better yet: Answer I reall…