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Click for San Francisco, California Forecast

San Francisco, USA

 

Make Useful Charts

Having been with Bay Area Bike Share for a few month, I am glad with their green bikes available around downtown. I also appreciate Bay Area Bike Share's openness in sharing their system metrics. However the system chart on their web page do not provide much useful information.

Official Chart

The slowly raise bar chart shows cumulative trips taken since launch. The chart may look boring, but as least the upward trend looks comforting, right? Wrong! A cumulative chart by construction can only go up. The comfort feeling is misleading. A more useful way is to chart the number of trips taken by week. Also, data from 5 cities are available individually. So why not plot them side by side for comparison. I did a little work to make an improved chart below.

Improved Chart

Some information immediate obvious from the chart is that nearly all trips were made in San Francisco, despite it only has half of the resources deployed. Clearly the bike share program is not working out in the Peninsula at all given their negligible usage. Secondly, there are ups and downs in usage that cannot be observed from the upward looking bar chart. After the first few months the usage has peaked at about 6,000 to 7,000 trips per week, then fallen sharply in December due to holidays. The January number has yet to recover to reach the usage last year.

This is not mean to be critical. It is just to demonstrate how an useful chart can inform us.

This is the link to the simple source code by Pandas.

2014.02.24 [] - comments

 

 

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