How does eSignal calc ema's?

[ndm123]

I'm not getting the same values for ema's that esignal is and was wondering how eSignal is calculating its values.

For example: eSignal shows the current value of a 34 period ema as 1137.59. The next close is 1138.00.

The formula I use to figure the next value is 1137.59 * (1 - 2/(34+1)) + 1138.00 * (2/(34+1))

This gives me a value of 1137.61 not the 1137.66 value eSignal shows.

If you could tell me where I'm wrong I'd appreciate it.

Thanks, Alan

[ACM]

Re: How does eSignal calc ema's?

Alan
You can find the algorithm used by eSignal in the ema.efs which is in the Library subfolder of the Formulas folder
Alex

Originally posted by ndm123
I'm not getting the same values for ema's that esignal is and was wondering how eSignal is calculating its values.

For example: eSignal shows the current value of a 34 period ema as 1137.59. The next close is 1138.00.

The formula I use to figure the next value is 1137.59 * (1 - 2/(34+1)) + 1138.00 * (2/(34+1))

This gives me a value of 1137.61 not the 1137.66 value eSignal shows.

If you could tell me where I'm wrong I'd appreciate it.

Thanks, Alan

[DolmenProp]

EMA calc

Hey,

There's an important factor to know when dealing with EMA's.

If you calculate an EMA of the S&P when there is 1000 bars loaded on the chart, you will get a different value for the same period EMA when you change the amount of bars from 1000 to say 5000.

This is because an EMA is an iterative function that depends on previous values. The very first value is a normal SMA and so the first 'n-period' bars that are loaded on the chart will determine the base of your EMA. Therefore when you change the amount of bars on the chart, you will change your initial condition and hence the value of the EMA.

This holds true for any iterative indicator like the MACD etc...