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Questions tagged [standard-deviation]

Standard deviation (represented by the symbol sigma, σ) shows how much variation or "dispersion" exists from the average (mean, or expected value).

The standard deviation of a random variable, statistical population, data set, or probability distribution is the square root of its . A standard deviation close to 0 indicates that the data points tend to be very close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.

The standard deviation of X is the quantity

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is there a way to compute the cluster_std of the dataset generated by make_blobs?

make_blobs() is used for generating isotropic Gaussian blobs for clustering. the param cluster_std is the standard deviation of the clusters. I generated a dataset: x, y = make_blobs(n_samples=100, centers=6, cluster_std=0.60,…
user10253483
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How to add error bars with standard deviation using ggplot2

I want to plot errorbars with standard deviation on my linear plot. I don't know why it is working with standard error only. What am I doing wrong? I've tried few methods but I keep getting errors. library(ggplot2) line = ggplot(alldata, aes(Time,…
Daria Cisło
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Postgres 9.5 Function to determine Normal Distribution

This questions answers how to find 2 standard deviations from the median: How to return median and values for x standard deviations from it in postgres However, it's only really useful if your data has a normal distribution. Is there a postgres…
moonshot
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Calculating Mean and Standard Deviation of a set of Angles in Excel

I am trying to calculate the mean and standard deviation within excel for a set of angles. This set could look like 356,340,352,2,5,8,358 or 178,-170,180,165,-177. I know that excel has built in tools to calculate the average and standard deviations…
R.W.K.
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Standard deviation of difference between dates in pandas group by

I have a dataframe of transactions. One of my columns is the date (datetime64[ns]). I'm making a group by of users (email as id). Something I'm interested in is the variability of time between orders of each user. So what I'm looking for in the…
Adrian Torrejón
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Standard deviation for float array JuliaLang

I'm trying to run std(list), where list is a Float array but I receive the next error: "MethodError: objects of type Array{Float64,1} are not callable Use square brackets [] for indexing an Array." And when using []: "ArgumentError: invalid index:…
C. Alexander
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Keras Feature Wise Center at Training and Prediction Time

I have had ImageDataGenerator implemented with featurewise_center=True, featurewise_std_normalization=True. I fit the generator to my training set (it learns some statistics) and train my model. All is well. After training is done and python is…
iDeepVision
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How can compute rolling window for standard deviation in R?

I tried to download the stock price and compute the standard deviation in rolling window. I found the library PerformanceAnalytics but they only have the rolling window for Mean not standard deviation.…
Homesand
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Plot a line graph with standard deviation in R

I have a dataframe similar to this one: myTable <- "ID Data Group 1 -50 5.0 2 -44 5.0 3 -48 5.0 4 -50 4.9 5 -44 4.9 6 -48 4.9 7 -48 4.9 …
schande
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Why does numpy.std() use abs()?

I checked the numpy library and found the following definition for the standard deviation in numpy: std = sqrt(mean(abs(x - x.mean())**2)) Why is the abs() function used? - Because mathematically the square of a number will be positive per…
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Python: how to get element-wise standard deviation of multiple arrays in a dataframe

I have a rather big dataframe (df) containing arrays and NaN in each cell, the first 3 rows look like this: df: A B C X [4, 8, 1, 1, 9] NaN [8, 2, 8, 4, 9] Y [4, 3, 4, 1, 5] [1, 2, 6,…
Svenno Nito
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Z score data by column in R

Below is a small, simplified version of my dataset. This data has already been log2 transformed. I would like to use the standard deviation to see how far each element is from the SD, treating each column as its own. I was wondering if this line…
Jakeeln
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How does r calculate the standard deviation and variance for non numeric data?

My task was to calculate the standard deviation and variance for four variables from a survey. Two of the variables are numerical but the other two aren't. I ran the following code: sapply(vclms[1:4], var) Vclms is the dataframe that the variables…
LoriDori
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Calculating SD of compass directions using Circular

My goal is to calculate a mean and standard deviation for a series of compass degrees. Since I may cross the 360/ 0 mark, I can't use the a standard mean or sd calculation. I've been using the circular packing in R, which seems to give me the…
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Calculating the standard deviation from columns of values and frequencies in Power BI

I am trying to calculate the standard deviation of a set of values in PowerBI and I am stuck. There are two columns in a table (days and count). This is a frequency distribution of a transportation lane. Days goes from 1 to 100, count is the number…
Roy Masrani
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