I have to read several files some in Excel format and some in CSV format. Some of the files have hundreds of columns. Is there a way to select several ranges of columns without specifying all the column names or positions? For example something like selecting columns 1 -10, 15, 17 and 50-100: I need to know h…
Tag: numpy
How to remove the space between subplots in matplotlib.pyplot?
I am working on a project in which I need to put together a plot grid of 10 rows and 3 columns. Although I have been able to make the plots and arrange the subplots, I was not able to produce a nice plot without white space such as this one below from gridspec documentatation.. I tried the following posts,
Appending matrix A with matrix B
Say I have two matrices A and B. For example, Is there a way to append A and B? Answer It sounds to me like you’re looking for np.hstack: np.vstack will work if you want to stack them downward:
Skip every nth index of numpy array
In order to do K-fold validation I would like to use slice a numpy array such that a view of the original array is made but with every nth element removed. For example: If n = 4 then the result would be Note: the numpy requirement is due to this being used for a machine learning assignment where the dependenc…
Convert a binary image to 2D array or Matrix in Python?
I’m new to image processing and I’m really having a hard time understanding stuff…so the idea is that how do you create a matrix from a binary image in python? to something like this: It not the same image though the point is there. Thank you for helping, I appreciate it cheers Answer Using …
Numpy Array Conditional Operation Mask?
Suppose you have an array: a = [ 0,1,0] [-1,2,1] [3,-4,2] And lets say you add 20 to everything b = [ 20, 21, 20] [ 19, 22, 21] [ 23, 16, 22] Now lets say I want to add the resulting b to the original array a but only in cases where a < 0 i.e at the index
Understanding scipy deconvolve
I’m trying to understand scipy.signal.deconvolve. From the mathematical point of view a convolution is just the multiplication in fourier space so I would expect that for two functions f and g: Deconvolve(Convolve(f,g) , g) == f In numpy/scipy this is either not the case or I’m missing an importan…
Error while reading image using cv2.imread() in Django views.py
I am trying to apply image processing on an image which i’m loading through cv2.imread() in Django’s views.py file, but i’m getting an AttributeError everytime. Following is the hierarchy views.py through which i’m trying to read temp321.jpg : Error which i’m getting: What am i d…
In Python, how would you check if a number is one of the integer types?
In Python, how could you check if the type of a number is an integer without checking each integer type, i.e., ‘int’, ‘numpy.int32’, or ‘numpy.int64’? I thought to try if int(val) == val but this does not work when a float is set to an integer value (not type). I want to fi…
How to access an item from S3 using boto3 and read() its contents
I have a method that fetches a file from a URL and converts it to OpenCV image I would like to use boto3 to access an object from s3 bucket and convert it to an image just like above method does. However, I’m not sure how to access an item from a bucket using boto3 and then further how to