How can i create a new matrix that equationally depends on another matrix?

i have a 1:1180 matrix that gives me variable velocity values and i need to create a new 1:1180 matrix to get transmission ratios for each velocity value.

i tried something but could not find a way so i am asking here. Please help.

Answer 1

[Kevin Phung]

Here's a potential solution:

gear = zeros(1,numel(v)); % initialize gear array
gear(and(v>=0,v<25)) = 1; %logical indexing 
gear(and(v>=25,v<50)) = 2;
gear(and(v>=50,v<70)) = 3;
gear(and(v>=70,v<90)) = 4;
gear(v>=90) = 5;)

Note: you should double check my inequalities. Im not sure where you want the bounds to be inclusive.

for example: v>=70 and v<90, versus v>=70 and v<=90

Let me know if this is what you needed

Answer 2

[Steven Lord]

I would use discretize.

% Generate some sample data for this example
v = randi([0, 100], 50, 1);

% Discretize into bins (the second input) with values given by the third input
% The right edge of the last bin should be at least as large as
%     the largest element in v
gear = discretize(v, [0; 25; 50; 70; 90; 100], (1:5).');

% Put the sample data and discretized data into a table for easy display
results = table(v, gear);

% Show the first several rows of the results table
head(results)

Depending on whether I was planning to use the gear information for later computation or for reporting to the user, I might create categorical data instead of numeric.

gearCategories = discretize(v, [0; 25; 50; 70; 90; 100], ...
    'categorical', ["first"; "second"; "third"; "fourth"; "fifth"]);
resultsCategorical = table(v, gearCategories);
head(resultsCategorical)

The IncludedEdge name-value pair argument may also be useful depending on whether you want 25 to be first or second gear etc.

[anil hamzacebi]

Thank you for your great answer!!!

I've tried your code and it's working well. i was not expecting two excellent help these quickly!!

i couldn't mark your respond i guess because that's one shot but i'm writing this comment also going to flag your respond as a solution i think it will help other people

Thank you again and wish you succes!!

[Steven Lord]

Flags are intended to report spam or other problems. [Think of the idea of a red flag.] If you want to indicate to people that this answer helped you even though it isn't the accepted answer, you can leave a comment to that effect (like you did) and/or vote for the answer.

Since this is my answer that got flagged, I'll leave it for someone else to remove the flag.