The composites are not available at the headend. They're calculated on the desktop by the chart app. You can easily replicate the same calculation. Try

df1 = ek.get_timeseries(['LCOc1'], ['OPEN','HIGH','LOW','CLOSE'])
df2 = ek.get_timeseries(['CLc1'], ['OPEN','HIGH','LOW','CLOSE'])
df3 = 3*df1 - 2*df2
df3.columns.name = '3*LCOc1-2*CL1'

@davide.costanzo, you can request both time series individually, and run the formula on the response:

df = ek.get_timeseries(['LCOc1', 'CLc1'], 'CLOSE')
df['composite'] = 3*df['LCOc1']-2*df['CLc1']
df.head()

thanks for your answer. I actually need to download ( HIGH , LOW, OPEN , CLOSE ) for the composite expression.

It is something I can already see using the 'chart' tab in the TR interface and using the composite expression:

3*"Q%LCOc1"-2*"Q%CLc1"

see attachment:

capture.png

So I just want to download that data.

thanks

Davide

Thank you for your answer.

This way of calculating the HIGH and LOW of the composite time series leads to a meaningless result.

This because , if A and B are two time series , it can be shown that

max(A-B) != max(A)-max(B)

and similarly

min(A-B) != min(A)-min(B) .

You can see this fact with an example. For example A= (0,3,0,2) and B = (3,4,1,4) . You would see that if one does (A-B) the correct (OPEN , HIGH, LOW, CLOSE) is (-3,2,-3,-2) .

Whereas simply subtracting

(OPEN , HIGH, LOW, CLOSE) - (OPEN ' , HIGH ', LOW ', CLOSE ')

would lead to (-3,-1,-1,-2) .

I verified in the 'Chart' tab , and indeed what you said is correct : that is the way it is calculated in Reuters.

I just wanted to point out the conceptual error.