‘list’ object has no attribute ‘shape’
Use numpy.array to use shape attribute. NOTE X.shape returns 3-items tuple for the given array; [n, T] = X.shape raises ValueError.
numpy
How do you get the magnitude of a vector in Numpy?
The function you’re after is numpy.linalg.norm. (I reckon it should be in base numpy as a property of an array — say x.norm() — but oh well). You can also feed in an optional ord for the nth order norm you want. Say you wanted the 1-norm: And so on.
deleting rows in numpy array
I have an array that might look like this: Notice that one of the rows has a zero value at the end. I want to delete any row that contains a zero, while keeping any row that contains non-zero values in all cells. But the array will have different numbers of rows every time it … Read more
Simple plot in python of a numpy array?
matplotlib.pyplot is a module; the function to plot is matplotlib.pyplot.plot. Thus, you should do A good place to learn more about this would be to read a matplotlib tutorial.
Bernoulli random number generator
I am asking on how the algorithm works to produce the numbers. – WhiteSolstice 35 mins ago Non-technical explanation If you pass n=1 to the Binomial distribution it is equivalent to the Bernoulli distribution. In this case the function could be thought of simulating coin flips. size=3 tells it to flip the coin three times and p=0.5 makes it a fair … Read more
How do I calculate percentiles with python/numpy?
You might be interested in the SciPy Stats package. It has the percentile function you’re after and many other statistical goodies. percentile() is available in numpy too. This ticket leads me to believe they won’t be integrating percentile() into numpy anytime soon
Overflow Error in Python’s numpy.exp function
As fuglede says, the issue here is that np.float64 can’t handle a number as large as exp(1234.1). Try using np.float128 instead: Note however, that there are certain quirks with using extended precision. It may not work on Windows; you don’t actually get the full 128 bits of precision; and you might lose the precision whenever the number passes through pure … Read more
Creating a Pandas DataFrame from a Numpy array: How do I specify the index column and column headers?
You need to specify data, index and columns to DataFrame constructor, as in: edit: as in the @joris comment, you may need to change above to np.int_(data[1:,1:]) to have correct data type.
3-dimensional array in numpy
New at Python and Numpy, trying to create 3-dimensional arrays. My problem is that the order of the dimensions are off compared to Matlab. In fact the order doesn’t make sense at all. Creating a matrix: In my world this should result in 2 rows, 3 columns and 4 depth dimensions and it should be … Read more
Overflow / math range error for log or exp
Line of code in question: Error: The sigmoid function is just 1/(1+ math.exp(-gamma)). I’m getting a math range error. Does anyone see why?