MEDIAN FILTER,FOR BASIC 3

[DANTHEELECTRICMAN]

HELLO: WELL I HAVE SPENT MOST OF THE DAY READING ONLINE ARTICLES ABOUT CODING FOR A MEDIAN FILTER. EVEN TRIED AN EXAMPLE,STILL OVER MY HEAD...I HAVE A 22 BIT ADC FOR A CO2 SENSOR,OUTPUT IS IN P.P.M., SO AT 5% GAS OR (50,000 PPM IS WHAT I WILL DISPLAY),THE READING IS A LITTLE JUMPY. LIKE 50,130, 50,090, 50,000, 50,065...SO FORTH. I HAVE READ THAT A MEDIAN FILTER IS A GREAT WAY TO RID THE NOISE FROM THE DATA. ANYWAY I CAN USE SOME EXPERTISE EVEN A CODE EXAMPLE IN BASIC...EVEN A GOOD BOOK OR WEBSITE TO STUDY WITH EXAMPLES. ANY HELP UNDERSTANDING HOW TO CODE THIS WILL BE VERY APPRECIATED....THANK YOU.P.S. SEE THE LINK ATTACHED.

 

[MacGyverS2000]

If a display is jumpy, just average the last 'X' values. After 10 reads, average the 10 readings and display that. When a new reading comes in, throw the oldest away and calculate a new average.


Dan - Owner

http://www.Hi-TecDesigns.com

 

[DANTHEELECTRICMAN]

THANKS FOR THE REPLY: I DID TRY THE AVERAGING TECHNIQUE,IT HELPS A LOT. THERE IS STILL THAT ANOMALOUS READING THAT POPS US DUE TO THE FACT I AVERAGE IN THE NOISE WITH THE ACTUAL DATA....FROM WHAT I READ ABOUT THE MEDIAN TYPE FILTER IT IS LESS LIKELY TO HAVE ANY OF THE NOISE IN THE FINAL AFTER THE MATH..IF YOU OR ANY ONE KNOWS OF A CODE EXAMPLE (IN BASIC) FOR A MEDIAN TYPE FILTER THAT WOULD BE HELPFUL..I SENT THE LINK FOR EMESYSTEMS.COM..(I GUESS I NEED MORE HELP THEN THAT???)..

 

[IRstuff]

Please refrain from using all caps; I don't get why no one has mentioned this to you before now.

Median filters work best with salt&pepper noise; for the example you gave, it will not make much of a difference. Nonetheless, there are examples on the Mathworks site for Matlab:

Or:

http://www.sourcecodeonline.com/list?q=median_filter_visual_basic

TTFN
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[DANTHEELECTRICMAN]

thanks for the reply: what is the matter with the caps????..anyway thanks for the link,actually i need code example in basic programing language for a running average routine...thank you all for any info..

 

[IRstuff]

All caps are inherently more difficult to read, since 99.99% of all text is in Sentence case or Title Case. Because most people are not used to reading all caps, they require more work to recognize and process the words. Moreover, in some circles, all caps is considered to be equivalent to shouting by an obnoxious person.

All text-based procedural languages are fairly similar in structure; multiplications are multiplications, arrays are usually fairly recognizable.

TTFN
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[MikeHalloran]

MacGyverS2000 gave you the algorithm in meta-code already.
Read his message again.


Mike Halloran
Pembroke Pines, FL, USA

 

[DANTHEELECTRICMAN]

OK THANKS FOR ALL THE INPUT....I REALLY DO APPRECIATE IT...I WAS ASKING FOR A CODE EXAMPLE...I FINALLY FIGURED IT OUT ON MY OWN,THANKS AGAIN...