What Is data analysis?Data analysis refers to the use of appropriate statistical analysis methods to collect a large amount of data analysis, they are summarized, understood and digested, in order to maximize the development of data functions, play the role of data.The purpose of data analysis is to concentrate and distill the information behind a large number of seemingly disorganized data, and summarize the inherent law of the research object. In practical work, data analysis can help managers
similar to the original data after filling, and the overall characteristics of the data are basically maintained during the filling process.Second, the abnormal valueOutliers are also very hated a kind of dirty data, outliers tend to pull up or pull down the overall situation of the data, in order to overcome the impact of outliers, we need to deal with outliers
All algorithms in machine learning rely on minimizing or maximizing a function, which we call "objective functions". The minimized set of functions is called the "loss function". The loss function is a measure of predicting the expected result performance of a predictive model. The most common way to find the minimum value of a function is "gradient descent". Think of the loss function as an undulating mountain range, where the gradient drops like a slide from the top of the mountain to reach th
The author's message: Abnormal value processing is generally divided into the following steps: Outlier detection, outlier filtering, outlier processing.Among the methods of outlier detection are: Box chart, simple statistic (such as observing extremum)The methods of handling outliers are: Delete method, interpolation method and substitution method.The mention of outliers has to say a word: robustness. is no
results of data) processing, otherwise it is easy to affect the final results. Common data preprocessing methods are shown in the following illustration:
1, Missing value processing
A missing value is a characteristic value that is missing from a row of data in a set of data. There are two ways to resolve missing values, one is to delete the line of data where the missing value is located, and the other is to add the missing value to the correct value.
2, abnormal value processing
Abnormal val
Whether it's data analysis, data visualization, or data mining, everything is based on data as the most basic element. Using Python for data analysis, the same most important step is how to import data into Python before you can implement data analysis, data visualization, data mining, and so on.
In this period of Python learning, we will take a detailed description of how Python obtains external data, from which we will learn about the following 4 areas of data acquisition:
8.4 Abnormal observation values8.4.1 Off-Group PointThe car package also provides a statistical test method for outlier points. The Outliertest () function can obtain the maximum normalized residual value bonferroni the adjusted p-value:> Library (CAR)> Outliertest (FIT)Rstudent unadjusted p-value Bonferonni pNevada 3.542929 0.00095088 0.047544You can see that Nevada is determined to be a outliers (p=0.048). Note that the function simply determines if
The importance of data distribution patterns
In the process of data analysis, the different distribution patterns of data will directly affect the choice of data analysis strategy. Therefore, it is very important to judge the distribution pattern of the data series. The common distribution pattern of data is normal distribution, random distribution (evenly distributed), Poisson distribution, exponential distribution, etc., but in data analysis, the most important distribution pattern is normal,
instruction-free learning. In other words, clustering is a method of information clustering based on the principle of information similarity in the case of pre-classification of classes. The purpose of clustering is to make the differences between objects belonging to the same category as small as possible, while the differences between objects on different categories are as large as possible. Example: to different consumer habits of the user clustering, respectively, push different services.Ou
Recently, when fiddling with data dispersion, I encountered a graph called box diagram (BoxPlot). It works well for discrete distributions of display data.The box was invented in 1977 by John Tukey, the American statistician John Tuki. It consists of five numeric points: Minimum (min), lower four (Q1), median (median), Upper four (Q3), Maximum (max). You can also add an average (mean) to the box diagram. Such as. The next four-digit, median, and four-bit digits form a "box with compartments". Cr
lead to confusion and output unreliable information.Outlier analysisOutlier analysis is a test of whether the data contains typographical errors and contains irrational data. Outliers, also known as outliers, behave as individual values in the sample, and their values deviate significantly from the rest of the observations. The analysis of outliers is also calle
First, outlier testOutliers include missing values, outliers, duplicate values, and inconsistent data.1. Basic functionsSummary can display the number of missing values for each variable.2, missing value testDetection of missing values should include: Number of missing values, missing value proportions, missing values, and full value data filtering.[Plain]View PlainCopy
#缺失值解决方案
Sum (complete.cases (saledata)) #is. NA (saledata)
Sum
concentrated, 50% of the unit price distribution in 30000-50000 of the interval, the interval is larger than other areas. Although the average unit price of Jianye District is slightly higher than Gu Lou, but the abnormal value of Gu Lou is very many, the price exceeds 50000 of the listing is numerous, the highest unit price has reached 100000, the unit price limit is far above Jianye District, but the Jianye District anomaly value is relatively few. In view of the above situation, Gulou Distri
limit, in F+3iqr and F-3IQR, draw two line segments, called the outer limit. The data represented by a point outside the inner limit is an outlier, where the outliers between the inside and outside limits are mild outliers (mild outliers) and extreme outliers other than outside limits (extreme
their own programming ability, for the future career development will also be a great help.Analysis Software main recommendation:SPSS series: Veteran statistical analysis software, SPSS Statistics (partial statistical function, market research), SPSS Modeler (partial data mining), without programming, easy to learn.SAS: Classic mining software, need programming.R: Open source software, the new popular, for
continuous addition equal to 500?
An array algorithm idea similar to the Yang Hui triangle
Solution to cattle and sheep grazing
A Method for batch processing Arrays
Statistical analysis:
Example 1 of parameter hypothesis test under 0-1 Population Distribution
Example 1 of parameter hypothesis test in the 0-1 Population Distribution (implemented by SPSS)
SPSS (| PASW) 18 Study Notes (1): Getting Started e
continuous features is moderate: If a sample of missing values is moderate, consider giving a step, then discretization, and adding Nan as a type to the attribute class.
The default value is less: Consider using the Fill method for processing. There are mean, majority, median fill, using the Randomforest model in Sklearn to fit the Data sample training model, and then to fill the missing value; Lagrange interpolation method.
It can be seen that monthlyincome (monthly income) and number
GH Blaede Wind turbine performance and load calculation integrated software package user interface intuitive to provide comprehensive model aerodynamic model control system application of dynamic response and other applicationsprogecad.2013.professional.v13.0.16.21 1CDprokon.v2.6.14 1CDIbm. Spss. Amos.v22 1CDIbm. Spss. Data.Collection.v7.Win32 1CDIbm. Spss. Data.
its category $y $ can.
One of the key factors in SVM is the support vector, what is the point of the support vector?According to the constraints in algorithm 1.1 $w _i (w \cdot x_i +b) –1 \ge 0$, the points in the data set satisfy the above constraints, the point $x _i$ support vector when the equation is established, that is, satisfies $w _i (w \cdot x_i +b) = 1 $properties:
The distance to the category plane is $1/|w| | $, because before we do not affect the results of the cas
Support Vector Machine (four)9 regular and non-split (regularization and the non-separable case)The case we discussed earlier is based on the linear separable assumptions of the sample, and when the sample is linearly non-tick, we can try to use kernel functions to map features to high dimensions, which is likely to be separable. However, after mapping we can not be 100% guaranteed to be divided. What to do, we need to adjust the model to ensure that in the case of non-point, we can also find th
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