Cutoff Threshold of data points

Question

Queena Edwards 2022-3-6

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1665034-cutoff-threshold-of-data-points

评论： Queena Edwards 2022-3-8

Rainfallevents.zip

I have calculated the sum of rainfall per rainfall event [RF_Total(x,:) ] and the sum of hours in that event [RF_Hours(x,:)]. I would like to remove rainfall events that are greater that 50.8 mm and more than 51h. This is what I've developed thus far.

(I've attached a compressed file containing the data that you would need for line 1 )

M1 = readmatrix('Pevents.txt');                     % Text File to Matrix 
NaNv = find(isnan(M1));                             % Numeric Indices Of 'NaN' Values
NaNv = [NaNv; size(M1,1)];                          % Last Index (Instead Of Last 'NaN') Is The End Of The Vector
Events = 1:numel(NaNv)-1;
for x = Events
    idxrng = NaNv(x)+2:NaNv(x+1)-1;
    RF_Vector{x,:} = M1(idxrng);                    % Vector Of Rainfall Events (Between 'NaN' Elements)
    RF_Hours(x,:) = numel(idxrng);                  % Number Of Hours In Each Event (h)
    RF_Total(x,:) = sum(M1(idxrng));                % Sum Of Rainfall Data (mm)
    
 
end
    t_holdrain = 50.8;                              % Cutoff Threshold of Rainfall Data(mm)
    t_holdhr = 51;                                  % Cutoff Threshold of Hourly Rainfall(h)
    y(x,:) = RF_Total(x,:);
    z(x,:) = RF_Hours(x,:);
      if  y(y > t_holdrain)& z(z > t_holdhr)         % Excluding rainfall greater than the threshold 
         
      end

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Answer 1

Image Analyst 2022-3-6

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1665034-cutoff-threshold-of-data-points#answer_911379

在 MATLAB Online 中打开

Try this:

y(x,:) = RF_Total(x,:);
z(x,:) = RF_Hours(x,:);
% Determine what rows we want to eliminate.
rowsToDelete =  (y > t_holdrain) & (z > t_holdhr);         % Excluding rainfall greater than the threshold 
% Now remove them from y and z
y(rowsToDelete, :) = [];
z(rowsToDelete, :) = [];

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Queena Edwards 2022-3-6

在 MATLAB Online 中打开

That didn't quite work because the numerical values were removed.

That's the format of RF_Total and RF_Hours. I would like to remove numbers greater than 50.8 for RF_Total and more than 51 for RF_Hours.

Can you try combining these two and then applying the conditions so that I get the values of the remaining there still.

Queena Edwards 2022-3-8

在 MATLAB Online 中打开

This is the result I'm getting. I'm not sure where the other data that are below the threshold went.

Queena Edwards 2022-3-8

在 MATLAB Online 中打开

M1 = readmatrix('Pevents.txt');                     % Text File to Matrix 
NaNv = find(isnan(M1));                             % Numeric Indices Of 'NaN' Values
NaNv = [NaNv; size(M1,1)];                          % Last Index (Instead Of Last 'NaN') Is The End Of The Vector
Events = 1:numel(NaNv)-1;
for x = Events
    idxrng = NaNv(x)+2:NaNv(x+1)-1;
    RF_Vector{x,:} = M1(idxrng);                    % Vector Of Rainfall Events (Between 'NaN' Elements)
    RF_Hours(x,:) = numel(idxrng);                  % Number Of Hours In Each Event (h)
    RF_Total(x,:) = sum(M1(idxrng));                % Sum Of Rainfall Data (mm)
    
 
end
Total_Hours = [ RF_Hours, RF_Total];