Python Data Visualization Transcripts
Chapter: Plotly
Lecture: Line bar area
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Now we're gonna look at some additional plot types and I'm going to create a new
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data frame that has the average fuel economy and the number of cars by year.
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And this will be a simple data frame that we'll use for plotting a line chart and some other plot types. So to walk through this I am grouping by I'm
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taking my data frame, grouping it by year in class. I don't want it to have a separate hierarchical index.
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That's why I set this to false and I'm aggregating our fuel cost to get them average and the vehicle to get the total number.
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This is why I added the vehicle column to our data frame so that we can count the number of vehicles per year.
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I'm rounding it to make it a little bit easier and this is our data frame So you can see for each year I can see the cars and what the
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average fuel cost was and how many fit into that. So now that we have this data, let's create a line chart to show what that averages over time.
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So now this is an interesting chart. We can look at the wagons over time and see how the fuel cost decreases and
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then we can do that for each of these other groups. So let me walk through what the line does. So I use my average by year.
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Class data frame, the X axis is the year. The wise the fuel cost. I'm telling it to group the lines together by class
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summary because if you see this data, we have multiple different entries per year.
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So it groups it by class summary which makes this really easy to show all these
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together and then we have our similar hover effects that we have seen earlier. So that's a good example for the line chart.
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And what's interesting what I like about plotly express that I can change it instead of just doing a line chart.
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Maybe I want to do an area chart and let's see what that looks like. So now the same basic code except I just changed it to PX.area shows
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an area chart so we can kind of see what that looks like over time. And then if you want to see a good old bar chart, change it to show a bar chart.
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So now I can see for each year by each class how that the number of vehicles per year. So in this case I said that the X.
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Is the year and then Y is vehicle.
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So if we just want to see how many vehicles there are per year in each class then it is very easy to see in this bar chart.