Info

此问题已关闭。 请重新打开它进行编辑或回答。

Matrix manipulation - smarter way to do this?

1 次查看（过去 30 天）
sas0701
sas0701 2013-12-4
关闭： MATLAB Answer Bot 2021-8-20
So,
1st column has trials from 1:300 but for each of the values there are multiple rows (this are samples in time - msecs)..
2nd column has conditions from 1:25.
See attached sample.txt
Each of the trials in column 1 is associated with a single value from column 2. Obviously multiple trials share the same conditions.
What I want is this:
1) Group conditions into eg. [2 5 7 10 ] or [1 4 5 6 7] etc.. I.e. any combination of conditions.
2) Group the corresponding trial data (Columns 3 to 10) separately. i.e. Column 3 from all the trials(1:300) that fall under Condition Group 1 should now become 1 matrix ordered in time.These should just stack on top of each other. I.e. same number of samples from each trial.
See attached Column5.txt (in this example trials 1 and 2 belonged to condition 5)
  3 个评论
显示 1更早的评论
dpb
dpb 2013-12-4
doc ismember
doc intersect % and friends
As said in response a day or two ago, look to the data object if have the Statistics Toolbox (never said yes/no)
doc accumarray
is useful with the above selection functions to build index vectors to fill arrays with results therefrom. Or, for single answers or for simply selecting subsets, look up 'logical addressing' in the documentation for how to address subsets of arrays based on conditional tests.
I suggest creating a much smaller sample of data as input and an example of the expected output and simply paste it into the window. 10 or even fewer lines should be plenty to illustrate the desire more simply than trying to parse the verbiage.
sas0701
sas0701 2013-12-5
yes, I have statistics toolbox..did you see attached sample.txt(eg. sample input) and Column5.txt(eg. desired result)?

此问题已关闭。

回答（1 个）

Walter Roberson
Walter Roberson 2013-12-4
Build the vector G(K) such that K is a condition number and G(K) is the number of the condition group it is to be placed in. Then G(column2) tells you which matrix number to toss each line into.
for T = 1 : size(YourData,1)
Matrices{G(YourData(T,2))}(end+1,:) = YourData(T,3:end);
end
  6 个评论
显示 4更早的评论
sas0701
sas0701 2013-12-5
Hi,
when there are N repetitions of "1" in column 1, then the output derived from column 3 should be N wide?
Yes.
Results from column 3 are separate from results from column 4 and column 5 etc..
i.e. one output file (Column 3) is
80 70
70 60
....
Then the results from Column 4 are
391 391
391 391 ..
etc..

此问题已关闭。

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by