Array of Numbers with error

I have a fraction that I am multiplying by an array of data to create a new array, but I want the new array of data to have error for the new values.

[KSSV]

Add some random noise....? Question is not clear.

[Justin Holladay]

I have an array of data for the number of traffic collisions from 1979-2018.

I have data from 2018 that shows the number of traffic collisions caused by speeding. I took speeding caused traffic collisions divided by total number of collisions for 2018 to get a percentage. I want to apply that percentage to the data from 1979-2018 to retrieve a set of data for number of traffic collisions caused by speeding for each of those years. I want the data to have error so that it is not following the exact percentage for each data point.

Answer 1

[Ameer Hamza]

What type of noise you you want to add? Following shows an example with normally distributed noise.

acc79_18; % data from 1979 to 2018
acc_speed_18; % speed accident in 2018

percent = acc_speed_18/acc79_18(end); % calculate fraction
percent_all_years = per*ones(1,numel(acc79_18)) + 0.01*randn(); % normally distributed noise with std of 0.01
percent_all_years(end) = per; % for 2018, noise should not be added

acc_speed_all_years = percent_all_years.*acc79_18;