Diverging Stacked Bar Chart#
This example shows a diverging stacked bar chart for sentiments towards a set of eight questions, displayed as percentages with neutral responses straddling the 0% mark.
import altair as alt
import pandas as pd
source = pd.DataFrame(
[
{
"question": "Question 1",
"type": "Strongly disagree",
"value": 24,
},
{
"question": "Question 1",
"type": "Disagree",
"value": 294,
},
{
"question": "Question 1",
"type": "Neither agree nor disagree",
"value": 594,
},
{
"question": "Question 1",
"type": "Agree",
"value": 1927,
},
{
"question": "Question 1",
"type": "Strongly agree",
"value": 376,
},
{
"question": "Question 2",
"type": "Strongly disagree",
"value": 2,
},
{
"question": "Question 2",
"type": "Disagree",
"value": 2,
},
{
"question": "Question 2",
"type": "Neither agree nor disagree",
"value": 0,
},
{
"question": "Question 2",
"type": "Agree",
"value": 7,
},
{
"question": "Question 2",
"type": "Strongly agree",
"value": 11,
},
{
"question": "Question 3",
"type": "Strongly disagree",
"value": 2,
},
{
"question": "Question 3",
"type": "Disagree",
"value": 0,
},
{
"question": "Question 3",
"type": "Neither agree nor disagree",
"value": 2,
},
{
"question": "Question 3",
"type": "Agree",
"value": 4,
},
{
"question": "Question 3",
"type": "Strongly agree",
"value": 2,
},
{
"question": "Question 4",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 4",
"type": "Disagree",
"value": 2,
},
{
"question": "Question 4",
"type": "Neither agree nor disagree",
"value": 1,
},
{
"question": "Question 4",
"type": "Agree",
"value": 7,
},
{
"question": "Question 4",
"type": "Strongly agree",
"value": 6,
},
{
"question": "Question 5",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 5",
"type": "Disagree",
"value": 1,
},
{
"question": "Question 5",
"type": "Neither agree nor disagree",
"value": 3,
},
{
"question": "Question 5",
"type": "Agree",
"value": 16,
},
{
"question": "Question 5",
"type": "Strongly agree",
"value": 4,
},
{
"question": "Question 6",
"type": "Strongly disagree",
"value": 1,
},
{
"question": "Question 6",
"type": "Disagree",
"value": 1,
},
{
"question": "Question 6",
"type": "Neither agree nor disagree",
"value": 2,
},
{
"question": "Question 6",
"type": "Agree",
"value": 9,
},
{
"question": "Question 6",
"type": "Strongly agree",
"value": 3,
},
{
"question": "Question 7",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 7",
"type": "Disagree",
"value": 0,
},
{
"question": "Question 7",
"type": "Neither agree nor disagree",
"value": 1,
},
{
"question": "Question 7",
"type": "Agree",
"value": 4,
},
{
"question": "Question 7",
"type": "Strongly agree",
"value": 0,
},
{
"question": "Question 8",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 8",
"type": "Disagree",
"value": 0,
},
{
"question": "Question 8",
"type": "Neither agree nor disagree",
"value": 0,
},
{
"question": "Question 8",
"type": "Agree",
"value": 0,
},
{
"question": "Question 8",
"type": "Strongly agree",
"value": 2,
},
]
)
# Add type_code that we can sort by
source["type_code"] = source["type"].map(
{
"Strongly disagree": -2,
"Disagree": -1,
"Neither agree nor disagree": 0,
"Agree": 1,
"Strongly agree": 2,
}
)
def compute_percentages(
group,
):
# Set type_code as index and sort
group = group.set_index("type_code").sort_index()
# Compute percentage of value with question group
perc = (group["value"] / group["value"].sum()) * 100
group["percentage"] = perc
# Compute percentage end, centered on "Neither agree nor disagree" (type_code 0)
# Note that we access the perc series via index which is based on 'type_code'.
group["percentage_end"] = perc.cumsum() - (perc[-2] + perc[-1] + perc[0] / 2)
# Compute percentage start by subtracting percent
group["percentage_start"] = group["percentage_end"] - perc
return group
source = source.groupby("question").apply(compute_percentages).reset_index(drop=True)
color_scale = alt.Scale(
domain=[
"Strongly disagree",
"Disagree",
"Neither agree nor disagree",
"Agree",
"Strongly agree",
],
range=["#c30d24", "#f3a583", "#cccccc", "#94c6da", "#1770ab"],
)
y_axis = alt.Axis(title="Question", offset=5, ticks=False, minExtent=60, domain=False)
alt.Chart(source).mark_bar().encode(
x="percentage_start:Q",
x2="percentage_end:Q",
y=alt.Y("question:N").axis(y_axis),
color=alt.Color("type:N").title("Response").scale(color_scale),
)
import altair as alt
import pandas as pd
source = pd.DataFrame(
[
{
"question": "Question 1",
"type": "Strongly disagree",
"value": 24,
},
{
"question": "Question 1",
"type": "Disagree",
"value": 294,
},
{
"question": "Question 1",
"type": "Neither agree nor disagree",
"value": 594,
},
{
"question": "Question 1",
"type": "Agree",
"value": 1927,
},
{
"question": "Question 1",
"type": "Strongly agree",
"value": 376,
},
{
"question": "Question 2",
"type": "Strongly disagree",
"value": 2,
},
{
"question": "Question 2",
"type": "Disagree",
"value": 2,
},
{
"question": "Question 2",
"type": "Neither agree nor disagree",
"value": 0,
},
{
"question": "Question 2",
"type": "Agree",
"value": 7,
},
{
"question": "Question 2",
"type": "Strongly agree",
"value": 11,
},
{
"question": "Question 3",
"type": "Strongly disagree",
"value": 2,
},
{
"question": "Question 3",
"type": "Disagree",
"value": 0,
},
{
"question": "Question 3",
"type": "Neither agree nor disagree",
"value": 2,
},
{
"question": "Question 3",
"type": "Agree",
"value": 4,
},
{
"question": "Question 3",
"type": "Strongly agree",
"value": 2,
},
{
"question": "Question 4",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 4",
"type": "Disagree",
"value": 2,
},
{
"question": "Question 4",
"type": "Neither agree nor disagree",
"value": 1,
},
{
"question": "Question 4",
"type": "Agree",
"value": 7,
},
{
"question": "Question 4",
"type": "Strongly agree",
"value": 6,
},
{
"question": "Question 5",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 5",
"type": "Disagree",
"value": 1,
},
{
"question": "Question 5",
"type": "Neither agree nor disagree",
"value": 3,
},
{
"question": "Question 5",
"type": "Agree",
"value": 16,
},
{
"question": "Question 5",
"type": "Strongly agree",
"value": 4,
},
{
"question": "Question 6",
"type": "Strongly disagree",
"value": 1,
},
{
"question": "Question 6",
"type": "Disagree",
"value": 1,
},
{
"question": "Question 6",
"type": "Neither agree nor disagree",
"value": 2,
},
{
"question": "Question 6",
"type": "Agree",
"value": 9,
},
{
"question": "Question 6",
"type": "Strongly agree",
"value": 3,
},
{
"question": "Question 7",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 7",
"type": "Disagree",
"value": 0,
},
{
"question": "Question 7",
"type": "Neither agree nor disagree",
"value": 1,
},
{
"question": "Question 7",
"type": "Agree",
"value": 4,
},
{
"question": "Question 7",
"type": "Strongly agree",
"value": 0,
},
{
"question": "Question 8",
"type": "Strongly disagree",
"value": 0,
},
{
"question": "Question 8",
"type": "Disagree",
"value": 0,
},
{
"question": "Question 8",
"type": "Neither agree nor disagree",
"value": 0,
},
{
"question": "Question 8",
"type": "Agree",
"value": 0,
},
{
"question": "Question 8",
"type": "Strongly agree",
"value": 2,
},
]
)
# Add type_code that we can sort by
source["type_code"] = source["type"].map(
{
"Strongly disagree": -2,
"Disagree": -1,
"Neither agree nor disagree": 0,
"Agree": 1,
"Strongly agree": 2,
}
)
def compute_percentages(
group,
):
# Set type_code as index and sort
group = group.set_index("type_code").sort_index()
# Compute percentage of value with question group
perc = (group["value"] / group["value"].sum()) * 100
group["percentage"] = perc
# Compute percentage end, centered on "Neither agree nor disagree" (type_code 0)
# Note that we access the perc series via index which is based on 'type_code'.
group["percentage_end"] = perc.cumsum() - (perc[-2] + perc[-1] + perc[0] / 2)
# Compute percentage start by subtracting percent
group["percentage_start"] = group["percentage_end"] - perc
return group
source = source.groupby("question").apply(compute_percentages).reset_index(drop=True)
color_scale = alt.Scale(
domain=[
"Strongly disagree",
"Disagree",
"Neither agree nor disagree",
"Agree",
"Strongly agree",
],
range=["#c30d24", "#f3a583", "#cccccc", "#94c6da", "#1770ab"],
)
y_axis = alt.Axis(title="Question", offset=5, ticks=False, minExtent=60, domain=False)
alt.Chart(source).mark_bar().encode(
x="percentage_start:Q",
x2="percentage_end:Q",
y=alt.Y("question:N", axis=y_axis),
color=alt.Color(
"type:N",
legend=alt.Legend(title="Response"),
scale=color_scale,
),
)