Quantopian's community platform is shutting down. Please read this post for more information and download your code.
Back to Community
Which pipeline is wrong?
qingshuo song
edited
Seeking Help Pipeline

It is a simplified question from the previous post, I do not know how to delete the earlier one.

I am following youtube python tutorial given by here
I simply copied the notebook in the webpage to generate and run a pipeline (pipeline1), which is shown in the second table.
Then I removed one line about ranking of factor to generate another pipeline (pipeline), which is shown in the first table.
These two tables give entirely different factor column on the same security.
Anybody could explain why these two are different, and which one shall be the correct one?

3 responses
Dan Whitnable

Well, they are two different factor values because they are two different factors. Unless, I'm not understanding your question, in the first cell your 'testing_factor' is

testing_factor = operation_ratios.operation_margin.latest

While in the second cell 'testing factor' is

testing_factor = testing_factor.rank(mask=universe, method='average')

One is the actual operation_margin value and the other is the rank of that value.

A couple of things, In general don't use the same variable name for two different things. You should maybe rename them 'testing_factor' and 'testing_factor_rank'. This becomes especially important in notebooks. This may not be happening here, but since notebooks can be executed in any order, using the same variable name can result in different values based upon the order in which the cells were run.

Anyway, I've changed your notebook to show the two different factors and their two different values. Does that clarify it?

qingshuo song

@Dan, Yes, your reply clarifies my question. I originally thought rank() reshuffles the order. Anyway, it's clear to me now and thanks.

Dan Whitnable

Ah yes, you may have been thinking of 'sort_values' which just reshuffles the rows. '.rank' is a very powerful method to normalize data which may have different ranges.

About Quantopian
Careers
Community
Events
Documentation
Academia
Lectures
Status
Facebook
Twitter
LinkedIn
YouTube
Terms of Use
Privacy Policy

The material on this website is provided for informational purposes only and does not constitute an offer to sell, a solicitation to buy, or a recommendation or endorsement for any security or strategy, nor does it constitute an offer to provide investment advisory services by Quantopian.

In addition, the material offers no opinion with respect to the suitability of any security or specific investment. No information contained herein should be regarded as a suggestion to engage in or refrain from any investment-related course of action as none of Quantopian nor any of its affiliates is undertaking to provide investment advice, act as an adviser to any plan or entity subject to the Employee Retirement Income Security Act of 1974, as amended, individual retirement account or individual retirement annuity, or give advice in a fiduciary capacity with respect to the materials presented herein. If you are an individual retirement or other investor, contact your financial advisor or other fiduciary unrelated to Quantopian about whether any given investment idea, strategy, product or service described herein may be appropriate for your circumstances. All investments involve risk, including loss of principal. Quantopian makes no guarantees as to the accuracy or completeness of the views expressed in the website. The views are subject to change, and may have become unreliable for various reasons, including changes in market conditions or economic circumstances.