Finding mean/SD of a group of population and mean/SD of remaining population within a data frame Question: I have a pandas data frame that looks like this: id age weight group 1 12 45 [10-20] 1 18 110 [10-20] 1 25 25 [20-30] 1 29 85 [20-30] 1 32 49 [30-40] 1 31 70 [30-40] …
Among investment histories how to find the cumulative sum option that proves to be more reliable for the long term? Question: In fact, not always the chart that reaches the highest peak of positive value when doing cumulative sum is the most reliable for long-term investments, because a single investment may have generated a very …
Generating random numbers with upper and lower standard deviation of the scatter Question: I have to produce randomly generated, normally distributed numbers, based on an astronomical table containing a most probable value and a standard deviation. The peculiar thing is that the standard deviation is not given by one, but two numbers – an upper …
Python: Weighted coefficient of variation Question: How can I calculate the weighted coefficient of variation (CV) over a NumPy array in Python? It’s okay to use any popular third-party Python package for this purpose. I can calculate the CV using scipy.stats.variation, but it’s not weighted. import numpy as np from scipy.stats import variation arr = …
Standard deviation in numpy Question: Here is my code: import numpy as np print(np.std(np.array([0,1]))) it produces 0.5 I am confident that this is incorrect. What am I doing wrong? Asked By: user1700890 || Source Answers: By default, numpy.std returns the population standard deviation, in which case np.std([0,1]) is correctly reported to be 0.5. If you …
Calculate the 3rd standard deviation for an array Question: Say, I have an array: import numpy as np x = np.array([0, 1, 2, 5, 6, 7, 8, 8, 8, 10, 29, 32, 45]) How can I calculate the 3rd standard deviation for it, so I could get the value of +3sigma as shown on the …
Why does numpy std() give a different result to matlab std()? Question: I try to convert matlab code to numpy and figured out that numpy has a different result with the std function. in matlab std([1,3,4,6]) ans = 2.0817 in numpy np.std([1,3,4,6]) 1.8027756377319946 Is this normal? And how should I handle this? Asked By: gustavgans …
Weighted standard deviation in NumPy Question: numpy.average() has a weights option, but numpy.std() does not. Does anyone have suggestions for a workaround? Asked By: YGA || Source Answers: There doesn’t appear to be such a function in numpy/scipy yet, but there is a ticket proposing this added functionality. Included there you will find Statistics.py which …
