RSI Calculation Discrepancy?

[sr243]

I tried to calculate the 14 day RSI using the method described at stockcharts.com (StockCharts.com - ChartSchool - Relative Strength Index (RSI))

I found that the values I got were the same as those from Metastock, but different from the ones from Google Finance and Yahoo Finance.

For example, for QQQQ, my RSI-14 values are
2009-06-25: 57.82
2009-06-26: 58.46
2009-06-29: 59.14

But, Google Finance gives:
2009-06-25: 45.09
2009-06-26: 46.97
2009-06-29: 44.75

Could someone enlighten me as to what's going on? Thanks.

 

[A Dashing Blade]

Checked that the data being fed into the Metastock & into Google/Yahoo is exactly the same?

 

[sr243]

Checked that the data being fed into the Metastock & into Google/Yahoo is exactly the same?

I used data directly from Yahoo.

 

[Dacamic]

As a guess, the Yahoo calculations are based upon 5-minute bars. If all calculations use daily bars (EOD data), their RSI values will be reasonably close to one another.