MATLAB: Selecting certain rows in an array

array select

Hi all, Matlab newbie here. I'm sure this is not a complicated question but I'm having no luck.

I have an array of 512 rows and 5 columns. Let's say column 1 is called A, 2 is called B, etc. I want to find row numbers where the value in A>0.10*max(A) and B<0.10*max(B), C<0.10*max(C), D<0.10*max(D). In other words, I want indexes where the value in only one column is greater than 10% of the max value in that column.

Any ideas? Thank you in advance, I learn a lot from these answers.

Best Answer

Supposing the array is R, then

cutoff = 0.10 * max(R);   %max goes column by colum
find( R(:,1) > cutoff(1) & R(:,2) < cutoff(2) & R(:,3) < cutoff(3) & R(:,4) < cutoff(4) )

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MATLAB: Agent repeats same sequence of actions each episode

Hi Braydon,

I am not really sure why you are only looking at the first two episodes. RL can take thousands of episodes to converge so the first few really don't give you enough information. As a matter of fact, I ran your models for 20 episodes and the action sequence was different after a few episodes or so. If nothing else, I would check the reward formulation since this would drive how the neural networks weights change and thus how actions are selected (in addition to exploration).

1.0000e-04

prev_state = 11.90 11.90 12.00 11.20

action = 0.00 0.00 0.00 0.00

new_state = 11.90 11.90 12.00 11.20

prev_state = 11.90 11.90 12.00 11.20

action = 0.10 0.10 -0.10 0.00

new_state = 12.00 12.00 11.90 11.20

prev_state = 12.00 12.00 11.90 11.20

action = -0.10 0.00 -0.10 0.10

new_state = 11.90 12.00 11.80 11.30

prev_state = 11.90 12.00 11.80 11.30

action = -0.10 0.10 0.00 -0.10

new_state = 11.80 12.00 11.80 11.20

prev_state = 11.80 12.00 11.80 11.20

action = 0.10 0.00 -0.10 0.00

new_state = 11.90 12.00 11.70 11.20

1.0000e-04

prev_state = 11.70 11.90 11.50 11.60

action = 0.00 0.00 0.00 0.00

new_state = 11.70 11.90 11.50 11.60

prev_state = 11.70 11.90 11.50 11.60

action = 0.10 0.10 -0.10 0.00

new_state = 11.80 12.00 11.40 11.60

prev_state = 11.80 12.00 11.40 11.60

action = -0.10 0.00 -0.10 0.10

new_state = 11.70 12.00 11.30 11.70

prev_state = 11.70 12.00 11.30 11.70

action = -0.10 0.10 0.00 -0.10

new_state = 11.60 12.00 11.30 11.60

prev_state = 11.60 12.00 11.30 11.60

action = 0.10 0.00 -0.10 0.00

new_state = 11.70 12.00 11.20 11.60

MATLAB: Find maximum value of array within specified range, consecutively

Assuming you know the ranges a priori, something like this might work. Note that I haven't tested this as I'm not going to try to transcribe your data.

% Define edges of ranges
rng = 0:0.011:0.2090
% Assign the data in column 2 to a predefined range
G = discretize(data(:,2),rng);
% Find the max value in each range
rMax = splitapply(@max,data(:,3),G)

Best Answer

Related Solutions

MATLAB: Agent repeats same sequence of actions each episode

MATLAB: Find maximum value of array within specified range, consecutively

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