Calculate Standard deviation in table

Question

Dion Theunissen 2021-6-25

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/865020-calculate-standard-deviation-in-table

回答： Erkan MSN 2022-1-24

采纳的回答： Chunru

Hi,

I have a table with 20 columns, I want to make a new column with the standard deviation of each row from column 4 to 6.

So after column 6 i want to have a column with the stdev of all rows of column 4:6.

How can I do that?

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Answer 1

Chunru 2021-6-25

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/865020-calculate-standard-deviation-in-table#answer_733185

在 MATLAB Online 中打开

a = array2table(rand(5,8))      % Sample table
a = 5×8 table
     Var1       Var2       Var3        Var4        Var5        Var6        Var7       Var8  
    _______    _______    _______    _________    _______    _________    _______    _______

     0.4022     0.9627    0.53548      0.35205    0.70636      0.89738    0.50393    0.44203
    0.96785    0.33289    0.57833      0.36493    0.84985    0.0031283    0.34461     0.3312
    0.29543    0.18861    0.91065     0.025623    0.40162      0.88419    0.24007    0.38235
    0.66403    0.19131    0.24685    0.0092594    0.10672      0.51052    0.79236    0.43115
    0.62483    0.95579    0.37075      0.11087    0.65024      0.55079    0.97985    0.57458
s = std(a{:, 4:6}, [], 2)   % std along rows (dim=2)
s = 5×1
    0.2767
    0.4249
    0.4304
    0.2658
    0.2870
b = [a table(s, 'VariableNames', {'std'})]   % combine with original
b = 5×9 table
     Var1       Var2       Var3        Var4        Var5        Var6        Var7       Var8        std  
    _______    _______    _______    _________    _______    _________    _______    _______    _______

     0.4022     0.9627    0.53548      0.35205    0.70636      0.89738    0.50393    0.44203    0.27671
    0.96785    0.33289    0.57833      0.36493    0.84985    0.0031283    0.34461     0.3312    0.42485
    0.29543    0.18861    0.91065     0.025623    0.40162      0.88419    0.24007    0.38235    0.43038
    0.66403    0.19131    0.24685    0.0092594    0.10672      0.51052    0.79236    0.43115    0.26577
    0.62483    0.95579    0.37075      0.11087    0.65024      0.55079    0.97985    0.57458    0.28704

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Dion Theunissen 2021-6-25

Thanks!

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Answer 2

Erkan MSN 2022-1-24

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/865020-calculate-standard-deviation-in-table#answer_880475

在 MATLAB Online 中打开

If you want to calculate the standard deviation of the whole table:

For example "cax" is table.

6424    5.2601    1.4691    0.7361    0.2771
0531    0.5722    1.8804    4.9636    0.9451
8084    1.6537    1.5916    0.8352    0.7740
7550    1.4221    1.7003    2.5646    0.4272
2935    2.5158    0.7656    1.0110    2.0810
0765    0.5390    1.9687    2.0829    0.4572
0493    1.4736    1.2810    1.0911    0.2073
1630    0.5679    2.8582    1.6006    0.4746
1625    0.7333    0.2623    0.6887    0.7897
9148    0.2886    3.1662    0.3645    0.5730
    
    std(cax,[],'all')
    ans =
0786e+03