How do I select max columns values based on certain column values?
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Dear Experiences ...
i have table look like the following..
Obs-name var1 var2 var3 ...... varn seg_id
ob1 0.12 0.14 0.17 1.2 1
ob2 1.2 0.2 0.14 0.0 1
ob3 1.5 0.3 1.5 7.2 2
ob4 2.4 4.5 2.2 0.0 3
.......................................etc.
i'm doing the following procedures:
1- i eliminate the first var content .. (obs name), using the following
T = readtable('data.xls');
Tnew=T(:,2:end)
2- calculate averages of all vars values based on segment_ID
Tavg=varfun(@mean,Tnew,'GroupingVariable','Seg_ID')
- now the tavg table includes all the average values for all vars based on Seg_ID.
Now i need to select the top var values (K) for every Seg_ID (K, where k=5).. then write table includes the Seg_ID , GroupCount , top K vars names look like the following table :
seg_id(1) Group count (3) var1 name var4 name var100 name
seg_id(2) group count (5) var2 name var3 name var15 name
seg_id(3) Group count (10)var1 name var12 name varn name
...etc..
attached file include a portion of my data table.
i will thanks any one can give a solution for this issue .. thanks
3 个评论
ranjith kumar reddy P
2017-4-4
Hello,
Please be clear. what do you want to calculate the mean of every vars which you are already doing it or mean of a particular var of values which belong to same segment ID?
ahmed obaid
2017-4-4
ahmed obaid
2017-4-4
采纳的回答
Not really clear on your question. If you're wanting to calculate the mean of the variables, grouped by seg_ID, then:
varfun(@mean, T, 'InputVariables', 2:width(T)-1, 'GroupingVariables', 'seg_ID')
I'm not sure what you want to do after that
edit: maybe you're looking for this function
function varargout = filterrows(rowvalues, varnames)
%function to be used with rowfun, returns the 5 highest column means of the rows together with their names, interlaced.
%requires 'SeparateInputs', false in the rowfun options.
rowmeans = mean(rowvalues, 1);
[~, order] = sort(rowmeans, 'descend');
varargout = [num2cell(rowmeans(order(1:5))); num2cell(varnames(order(1:5)))]; %will be reshaped into a row vector by rowfun
end
which you can use with rowfun:
rowfun(@(rowvalues) filterrows(rowvalues, T.Properties.VariableNames(2:end-1)), ...
T, ...
'InputVariables', 2:width(T)-1, ...
'GroupingVariables', 'seg_ID', ...
'SeparateInputs', false, ...
'NumOutputs', 10)
Not sure it's a good idea, though.
3 个评论
ahmed obaid
2017-4-4
may i'm not explain my problem in a proper way, any way consider the following table T:
----------------------------------------------------------
ok now let us calculate the mean of every var values (A...I) based on Seg number (1..4), as in your first line code.
Tavg=varfun(@mean, T, 'InputVariables', 2:width(T)-1, 'GroupingVariables', 'Seg')
now the mean of var values are calculated based on (Seg) number ...
my requirement as follow: - now the vars includes different values over all (Seg) number .. i need to select for every segment (Seg=1,,4) what are the top (max) k vars name (suppose K=5) , as follow :
- -consider Seg=1 vars , the top K-var ( based on mean values) in descending order are ( I,B,H,C and D)
- -consider Seg=2 vars the top k-vars (based on mean values ) in descending order are (I,H and B.. remaining vars are 0's values so any 2 vars names no problem) and so on for others...
final table (Tfin) includes the following output :
seg top (K) var names
1 I,B,H,C,D
2 I,H,B,A,C
3..etc.
attached portion of my table in simble way
Guillaume
2017-4-4
Isn't the output of my rowfun code (all the bit after edit) exactly what you've described?
If it's just the variable names, without the values that you want, then changing it to
function varargout = filterrows(rowvalues, varnames)
%function to be used with rowfun, returns the 5 highest column means of the rows together with their names, interlaced.
%requires 'SeparateInputs', false in the rowfun options.
rowmeans = mean(rowvalues, 1);
[~, order] = sort(rowmeans, 'descend');
varargout = num2cell(varnames(order(1:5)));
end
and calling it with
rowfun(@(rowvalues) filterrows(rowvalues, T.Properties.VariableNames(2:end-1)), ...
T, ...
'InputVariables', 2:width(T)-1, ...
'GroupingVariables', 'seg_ID', ...
'SeparateInputs', false, ...
'NumOutputs', 5)
will give you that.
ahmed obaid
2017-4-4
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