Bollinger bands

[makincash]

Hi Jerry,

I am not sure if this is a bug or just the way the bollinger bands are implemented in Medved. I attached a couple of pics of the same symbol across two other platforms Questrade and Tradingview. In Medved the bollinger bands don't continue to flow but drop off when there is low/no volume.

On other thing I noticed was that the RSI in Medved was quite far off what the other two had.  Eg. at 1:00pm today MT 77 with wilder checked,, 81 without it checked,  Questrade 53, Tradingview 53.

 

Cheers,

Jeff

 

tradingv

[Mike Medved]

MT was basically counting 0 vol periods as candles at the close of previous with-volume candles, for the purpose of calculating the standard deviation (as well as for the purpose of calculating the central MA).

 

The central-MA calculation is fine for that. But apparently your other sources do not do that for the StDev calculation. I guess that's another way to look at it although I can see merit in our method as well.

 

I changed it in the calc. Email jerry to get the new ver that has that.

[makincash]

Hi Mike,

Gave it a try and it smoothed out the bands ie made them continue to flow instead of cut off.  I still see it occurring in historical charts, do you need to adjust that separately?

[makincash]

Hi  Mike,

Something else I noticed was the Medved 20 SMA (center line) in the charts seems to be much more variable (not as smooth) as the one in the Questrade and Tradingview charts. A good example is the hump of the very left of the MedVed chart in the 1st post at 9:52 on the 12th.   This I assume translates back to the bollinger bands upper and lower line flow.  From an visual perspective it makes the chart more distracting to read.  Not sure if MedVed is just more accurate in its representation then the other charting tools or if they use some kind of smoothing algorithm.  I have attached a pic after the change you made already for the bollinger bands to this post.  

 

Cheers,

Jeff

[Mike Medved]

Hm - the historical charts have days with no volume?

 

7 hours ago, makincash said:

Hi Mike,

Gave it a try and it smoothed out the bands ie made them continue to flow instead of cut off.  I still see it occurring in historical charts, do you need to adjust that separately?

 

 

[Mike Medved]

The hump is there not because of SMA but, I presume, because the StDev jumped.

SMA in MT, as I pointed out above, takes no-volume gaps to have the same value as the previous candle for the purpose of calculating the period's average.

So if you have (with - being the no-volume candle)

10 10 12 - - 10 12  - the SMA(5) would be (12+10+12+12+12)/5 = 11.6

while if the -s were skipped, it would be (12+10+12+10+10)/5 = 10.8

 

I think not skipping the empties presents a more representative picture of the average for the time period.

 

 

6 hours ago, makincash said:

Hi  Mike,

Something else I noticed was the Medved 20 SMA (center line) in the charts seems to be much more variable (not as smooth) as the one in the Questrade and Tradingview charts. A good example is the hump of the very left of the MedVed chart in the 1st post at 9:52 on the 12th.   This I assume translates back to the bollinger bands upper and lower line flow.  From an visual perspective it makes the chart more distracting to read.  Not sure if MedVed is just more accurate in its representation then the other charting tools or if they use some kind of smoothing algorithm.  I have attached a pic after the change you made already for the bollinger bands to this post.  

 

Cheers,

Jeff

 

 

[makincash]

Oops thought I posted the pic from the historical. 

Thanks for the info on the SMA.

Jeff