Complete the code to calculate the exponential moving average of the 'price' column with a span of 3.
df['ema'] = df['price'].[1](span=3).mean()
The ewm() method creates an exponential weighted object to calculate the exponential moving average. Using mean() on it computes the EMA.
Complete the code to calculate the exponential moving average with a halflife of 2.
df['ema'] = df['price'].ewm([1]=2).mean()
The halflife parameter specifies the period over which the weights decrease by half in the exponential moving average calculation.
Fix the error in the code to correctly calculate the EMA with center of mass 1.5.
df['ema'] = df['price'].ewm(com=[1]).mean()
The com parameter expects a numeric value, not a string or incorrect syntax. Use 1.5 as a float number.
Fill both blanks to create an EMA with alpha 0.3 and ignore NaN values in the calculation.
df['ema'] = df['price'].ewm([1]=0.3, [2]=True).mean()
The alpha parameter sets the smoothing factor. The ignore_na=True parameter makes the calculation ignore NaN values properly.
Fill all three blanks to create a dictionary comprehension that calculates EMA for each column in df with span 4 and stores results in a new dict.
ema_dict = [1]: df[col].ewm([2]=4).mean() for col in df.columns if col [3] 'price'
This comprehension creates a dictionary with keys as column names and values as their EMA with span 4. It excludes the 'price' column using '!='.