Calculate mean of certain values in a vector

Hi!

I have two problems I'd need some help with.

I have a column vector (25 x 1) with positive and negative values. It has the following values:

1716000

0

-2400000

-5124000

880000

-51000

-192000

656000

165000

702000

1456000

1700000

-550000

46000

8272000

-660000

-162000

2000

22000

210000

2817000

285000

-1400000

840000

570000

First problem: Out of these values, I would first like to calculate the average (mean) of all the values that are not negative.

I tried the following script, but it gives a weird answer of 0,68:

OnlyPositives = profit>=0;
avgProfitNoLoss = mean(OnlyPositives)

I don't know why it gives me the answer of 0,68 so the first question is how I can correct this.

The next step then is to calculate the average of the values that are zero and the values that are negative. But, the first problem above needs to be addressed first.

Thank you in advance for any help/suggestions!

Answer 1

[Star Strider]

You created a logical vector with ‘OnlyPositives’. Use it to calculate the mean as:

avgProfitNoLoss = mean(profit(OnlyPositives))

producing:

avgProfitNoLoss =
          1196411.76470588

that is likely the result you want.

The average of the values that are zero will be zero, so you can avoid that calculation.

[Daniel Miller]

Wonderful, this solved the problem. Thank you very much, Star Strider!

[Star Strider]

As always, my pleasure!

[Carlos Maqueda]

I had the same problem, working with digital signs (+,-). Thanks too