Running Average in Comp
24 Apr 2009 06:51 #141
by alex_joni
Replied by alex_joni on topic Re:Running Average in Comp
BigJohnT wrote:
Usually you use another variable (lets call it last) which point to where you last entered a value.
so you do
For the average you have to add them, then divide by 10. There are other "smarter" algorithms, but for 10 items it's not worth the extra effort.
otoh, the lowpass filter should be ok for you
Regards,
Alex
variable float myarray[10];
Is there a slick way to push a new number into an array then get the average?
Usually you use another variable (lets call it last) which point to where you last entered a value.
so you do
myarray[last++] = newvalue;
if (last >= 10) last = 0; // should only need ==10, but it can't hurt to be a bit more paranoid ;)For the average you have to add them, then divide by 10. There are other "smarter" algorithms, but for 10 items it's not worth the extra effort.
otoh, the lowpass filter should be ok for you
Regards,
Alex
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09 Mar 2010 14:08 #2255
by tom3p
Replied by tom3p on topic Re:Running Average in Comp
i've done running averages with weighting of the new information
like 20 parts of old value plus 1 part of new divided by 21
the more old stuff in the recipe makes new stuff matter less
less stuff in the recipe makes new stuff matter more
by adjusting the the number of samples, you vary between very responsive to sluggish
its easy to imagine the new value influencing the result a lot with (1old + 1 new) /2
and not making a big diff with (20 old + 1 new)/21
maybe this is what lowpass does, but 'lowpass' sure doesnt remind me of this concept
if so, make an alias called 'runningAvg'
like 20 parts of old value plus 1 part of new divided by 21
the more old stuff in the recipe makes new stuff matter less
less stuff in the recipe makes new stuff matter more
by adjusting the the number of samples, you vary between very responsive to sluggish
its easy to imagine the new value influencing the result a lot with (1old + 1 new) /2
and not making a big diff with (20 old + 1 new)/21
maybe this is what lowpass does, but 'lowpass' sure doesnt remind me of this concept
if so, make an alias called 'runningAvg'
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