numpy

问题 I'm trying to merge couple of dataframes from HomeCredit Kaggle competion according to the data schema. I did following: train = pd.read_csv('~/Documents/HomeCredit/application_train.csv') bureau = pd.read_csv('~/Documents/HomeCredit/bureau.csv') bureau_balance = pd.read_csv('~/Documents/HomeCredit/bureau_balance.csv') train = train.merge(bureau,how='outer',left_on=['SK_ID_CURR'],right_on=['SK_ID_CURR']) train = train.merge(bureau_balance,how='inner',left_on=['SK_ID_BUREAU'],right_on=['SK_ID

问题 I am trying to plot the S-shape cumulative distribution function (cdf) curve of a normal distribution. However, I ended up with a uniform distribution. What am I doing wrong? Test Script import numpy as np from numpy.random import default_rng from scipy.stats import norm import matplotlib.pyplot as plt siz = 1000 rg = default_rng( 12345 ) a = rg.random(size=siz) rg = default_rng( 12345 ) b = norm.rvs(size=siz, random_state=rg) c = norm.cdf(b) print( 'a = ', a) print( 'b = ', b) print( 'c = ',

问题 Assume I have a list of strings and I want to convert it to the numpy array. For example I have A=A=['[1 2 3 4 5 6 7]','[8 9 10 11 12 13 14]'] print(A) ['[1 2 3 4 5 6 7]', '[8 9 10 11 12 13 14]'] I want my output to be like the following : a matrix of 2 by 7 [1 2 3 4 5 6 7;8 9 10 11 12 13 14] What I have tried thus far is the following: m=len(A) M=[] for ii in range(m): temp=A[ii] temp=temp.strip('[') temp=temp.strip(']') M.append(temp) print(np.asarray(M)) however my output is the following:

问题 I am trying to learn tensorflow, and I was following a demo tutorial (https://www.tensorflow.org/tutorials/keras/basic_text_classification) The error report is telling me "Error when checking target: expected dense_1 to have shape (1,) but got array with shape (256,)" Can someone explain to me why this won't work? train_data = keras.preprocessing.sequence.pad_sequences(train_data, value=word_index["<PAD>"], padding='post', maxlen=256) #max length test_data = keras.preprocessing.sequence.pad

问题 I have just made the following mistake: a = np.array([0,3,2, 1]) a[0] = .001 I was expecting 0 to be replaced by .001 (and the dtype of my numpy array to automatically switch from int to float). However, print (a) returns: array([0, 3, 2, 1]) Can somebody explain why numpy is doing that? I am confused because multiplying my array of integers by a floating point number will automatically change dtype to float: b = a*.1 print (b) array([0. , 0.3, 0.2, 0.1]) Is there a way to constrain numpy to

问题 I have 9 arrays that I want to manipulate to find all possible combinations, so that the name of the resulting array tells me which arrays have been combined. For example: a1_a2 = array1 - array2 a1_a3 = array1 - array3 a1_a4 = array1 - array4 . . . a9_a6 = array9 - array6 a9_a7 = array9 - array7 a9_a8 = array9 - array8 Obviously I could hardcode it, but how could I do it in a loop? I thought of writing a function for it, something like: def combineArrays(array1, array2): result_name = name

问题 Let's say we have a 2D array, image , eg. 20x20. I would like add a method, called 'imshow' to this object such that whenever I do image.imshow(**kwargs) ), the method imshow will make a call of Matplotlib.pyplot.imshow What is the best way to do this? I was thinking of writing a class with an inheritance from numpy.ndarray, and adding a method 'imshow'. 回答1: Just found the answer (thanks to How can a class that inherits from a NumPy array change its own values?)! class array(np.ndarray): def

问题 After checking the documentation and this question I tried to split a numpy array and a sparse scipy matrices as follows: >>>print(X.shape) (2399, 39999) >>>print(type(X)) <class 'scipy.sparse.csr.csr_matrix'> >>>print(X.toarray()) [[0 0 0 ..., 0 0 0] [0 0 0 ..., 0 0 0] [0 0 0 ..., 0 0 0] ..., [0 0 0 ..., 0 0 0] [0 0 0 ..., 0 0 0] [0 0 0 ..., 0 0 0]] Then: new_array = np.split(X,3) Out: ValueError: array split does not result in an equal division Then I tried to: new_array = np.hsplit(X,3)

问题 I'm starting to learn python. So the first thing I did was install python, in this case ubuntu 16.04 LTS, since in this system python is already installed. As a first test, I tried to run a simple program with numpy library, but program n does not run, it displays the following error: import sitecustomize' failed; use -v for traceback <type 'numpy.ndarray'> It seems to me that Spyder failed to import the numpy library, although I've already called it by the terminal and it came, that is, it's

问题 I'm starting to learn python. So the first thing I did was install python, in this case ubuntu 16.04 LTS, since in this system python is already installed. As a first test, I tried to run a simple program with numpy library, but program n does not run, it displays the following error: import sitecustomize' failed; use -v for traceback <type 'numpy.ndarray'> It seems to me that Spyder failed to import the numpy library, although I've already called it by the terminal and it came, that is, it's