Conditional if statement solution

I will greatly appreciate it if any one assist me in solving this problem in Matlab code

For instance I have a list of values = 3 4 6 3 4 5 10 7 4 5 3 4

The code contains two if statement

if values > 9

in this case it is in position 7 : display the positions in values that meet condition ( if value > 9) in the example above it is the 7th position (10)

then calculate the 5 numbers before and after including position 7th (10) itself an example

average = (4 + 5 + 10 + 7 + 4 )/5 = 6

if (average > 9)

true changes showing ( 7th position = 10 )

else

false changes (7th position = 10 )

end if statement

end if statement

The answer is false change detection

I will like to be assisted with the code as I want to apply these to large data

Thanks in advance

[Geoff Hayes]

Tino - what happens if there are more than one element in the array with a value greater than 9? Do you need to apply the same logic to all elements that satisfy this condition?

[Tino]

Yes Geoff it is applicable for all elements with a value greater than 9 even if it is more than one.

[Geoff Hayes]

So you will want to find all elements that are greater than nine and then apply the logic to each one presumably storing the result of each in an array.

[Tino]

Yes Geoff with a discription if they are true changes or false changes

Answer 1

[Rik]

In Matlab calculating parameters for the entire array at once is almost always faster than a loop. My code below uses the find function (as Geoff hinted at), and it uses a convolution to find the moving average for each position. You should check if this matches your requirements for the edge cases. If you want to display the results in a different way, you should be able to add code that suits your need.

values =[3 4 6 3 4 5 10 7 4 5 3 4];

window=ones(1,5)/5;
avg=conv(values,window,'same');
true_changes=find( values>9 & avg>9 );
false_changes=find( values>9 & avg<=9 );