Mean of selected range of a matrix based on a range of values from another matrix

Hello everyone,

I have a mat file (attached) containing 4 parameters: month, sa, ta, and sig. My intention is to get the mean and standard deviation from each month of sa and ta at a specific range of sig (let's say the value of sig : 27.4 - 27.5).

So, the intended output should be like this:

Thank you!

[Shivam Gothi]

Hello @Adi Purwandana,

What I understand is, you want to find the mean and the standard deviation of only those set of values of "ta" and "sa" for which "sig" is within the range of 27.4 - 27.5. Also, the "sig_range" is different for different months.

Is my understanding of question corrrect ?

[Adi Purwandana]

@Shivam Gothi Exactly

Answer 1

[Voss]

load('data_my.mat')

T = table(month,sa,ta,sig);

% only sig 27.4 to 27.5
idx = sig >= 27.4 & sig < 27.5;
G = groupsummary(T(idx,:),'month',{'mean','std'},{'sa','ta'})

G = 3x6 table
    month    GroupCount    mean_sa     std_sa      mean_ta    std_ta 
    _____    __________    _______    _________    _______    _______

     10         3360       34.611     0.0047013    3.4963     0.27562
     11         4320       34.608     0.0063067    3.4344     0.33247
     12          792        34.61     0.0081189    3.3022     0.38516

% for reference, all sig
G = groupsummary(T,'month',{'mean','std'},{'sa','ta'})

G = 12x6 table
    month    GroupCount    mean_sa     std_sa      mean_ta    std_ta 
    _____    __________    _______    _________    _______    _______

      1         4464       34.609     0.0081535    3.2774     0.35106
      2         4032       34.608      0.006585    3.4279      0.3524
      3         4464       34.609     0.0056887    3.4532     0.31757
      4         4320       34.611     0.0049732    3.5148     0.32073
      5         4464       34.612      0.005491    3.4808     0.33566
      6         4320        34.61     0.0058029    3.4186     0.33016
      7         4464        34.61      0.006245     3.444     0.35342
      8         4464       34.609     0.0065816    3.4272     0.35374
      9         2203       34.612     0.0081435    3.2829     0.44816
     10         3361       34.611      0.004702    3.4963     0.27559
     11         4320       34.608     0.0063067    3.4344     0.33247
     12         4464       34.609      0.007599    3.3792     0.36885

[Adi Purwandana]

Perfect! Thank you, my additional following question if you don't mind, could you please present the boxchart/boxplot for each month of that specified range of sig (sig >= 27.4 & sig < 27.5)?

[Voss]

load('data_my.mat')

T = table(month,sa,ta,sig);

% only sig 27.4 to 27.5
idx = sig >= 27.4 & sig < 27.5;

boxchart(T{idx,'month'},T{idx,'sa'})

boxchart(T{idx,'month'},T{idx,'ta'})

[Adi Purwandana]

Great, thank you @Voss!

[Voss]

You're welcome! Any questions, let me know.