averaging lower percentile readings

[majeed]

I am trying to find the average of 10% of my readings( or the lower 10% of all my readings. Lets say I have the following readings, 1, 3, 86, 8, 99, 9, 4, 4, 3, 5, 7, 8, 9, 4, 67,90,34,89,90, 78, 89, 56, 144, 44, 55,etc. Let say I have 100 readings. How do I choose the ten lowest and find their average using labVIEW6.0?

[chilly_charly]

1/ Sort the data, using "Sort 1D Array" (Array subpalette)

2/ Use "Array subset" to get the N lowest elements. N can be calculated using "Array size", and dividing by the apparopriate number (10 in your cadse)

3/ Calculate the mean (Analyze>Matehmatics>Probabilty and statistics>Mean.vi)

[majeed]

"2/ Use "Array subset" to get the N lowest elements. N can be calculated using "Array size", and dividing by the apparopriate number (10 in your cadse)" I have got the array subset vi. How to get N lowest. Where is "array size". Let's say N=10 and the array size is 100. I am using labVIEW6.0. Do I right click and choose constant? or how? Any help would be apperciated.

[chilly_charly]

After the sort operation, the elements are ordered from lowest to highest. Accordingly, the N lowest elements are the N first elements. You just need to wire the length input since the index inpuit default to zero.

If you look with some attention into the array subpalette, you will found that the Array Size function is the very first :O.

Seems that you need to spend some time to get familiar with the most basic LabVIEW functions 😉

[labview1958]

I am also doing something similiar. I have attached a vi. Does this reflect the topic?

[labview1958]

I have attached a vi. Does it calculates the mean of the five lowest values?

[Dennis_Knutson]

No. It takes the mean of all elements except for the lowest five. You want to specify an index of 0 and a length of 5. You've specified an index of 5 and no length. That does just the opposite and a simple test should have showed the error.

[labview1958]

I have attached a revised vi. Is that right?

[Dennis_Knutson]

Yes. You could also just leave the index input unwired and it will automatically default to 0.