I am making a scatter plot with the geyser dataset from seaborn. I am coloring the points based on the 'kind' column but for some reason, the legend only shows 'long' but leaves out 'short'. I don't know what I am missing. I also was wondering if there is a simpler way to color code the data one that does not use a for-loop. Thanks!

x = geyser_df['waiting']
y = geyser_df['duration']
col = []

for i in range(len(geyser_df)):
    if (geyser_df['kind'][i] == 'short'):
        col.append('MediumVioletRed')
    elif(geyser_df['kind'][i] == 'long'):
        col.append('Navy')

plt.scatter(x, y, c=col)
plt.legend(('long','short'))
plt.xlabel('Waiting')
plt.ylabel("Duration")
plt.suptitle("Waiting vs Duration")
plt.show()

CodePudding user response：

 You're passing x = geyser_df ['waiting'] and y = geyser_df ['duration'] as a single dataset which causes plt.scatter to only use as label="long" as legend (one per dataset). I don't have enough experience using this type of libraries but to reproduce the example you describe you need to write a program like this:

long = [[], []]
short = [[], []]
col=['MediumVioletRed', 'Navy']

for i in range(len(geyser_df["kind"])):
  if (geyser_df["kind"][i] == "long"):
      long[0].append([geyser_df['waiting'][i]])
      long[1].append([geyser_df['duration'][i]])
  else:
      short[0].append([geyser_df['waiting'][i]])
      short[1].append([geyser_df['duration'][i]])

plt.scatter(long[0], long[1], c=col[1], label="long")
plt.scatter(short[0], short[1], c=col[0], label="short")

plt.legend()
plt.xlabel('Waiting')
plt.ylabel("Duration")
plt.suptitle("Waiting vs Duration")
plt.show()

CodePudding user response：

• The correct way to do this with pandas is with
  • The easiest way is with seaborn, which is a high-level API for matplotlib
    • sns.scatterplot
    • sns.relplot

  fig, ax = plt.subplots(figsize=(6, 4))
  sns.scatterplot(data=df, x='waiting', y='duration', hue='kind', palette=['Navy', 'MediumVioletRed'], ax=ax)
  

  sns.relplot(data=df, x='waiting', y='duration', hue='kind', palette=['Navy', 'MediumVioletRed'], height=4, aspect=1.5)