2.2 Integration with pandas DataFrames

%matplotlib inline
import matplotlib.pyplot as plt
import pandas as pd
import signac

project = signac.init_project("projects/dataframe-example")

We create a project with some sample data.

funcs = {
    "abs": abs,
    "square": lambda x: x**2,
}

for x in range(-5, 6):
    job = project.open_job({"x": x})
    for name, func in funcs.items():
        job.document[name] = func(x)

Let’s first create a basic DataFrame from our project:

df = project.to_dataframe()
df = df.sort_values("sp.x")
df

	sp.x	doc.abs	doc.square
3c5a15f6f26125f2902f38ff28a94072	-5	5	25
22749661e1ac649551a29953c93c9e92	-4	4	16
9e892a750ef4bf5ca73069c249088d40	-3	3	9
46049d7a2b36731d20af67766aadfeea	-2	2	4
c887a273c9a550e883f09187b0e28eb7	-1	1	1
eff8ca15e7ca8ae5c09f011f997b34df	0	0	0
27958648a9e57fcd66ae5e31ff3359e9	1	1	1
46c24d61c4220f8b62d2ae73d686ec18	2	2	4
d832cd5075866a4973a78377f49f58a5	3	3	9
9cdfeafe274b4f1762f0bf885ca055b7	4	4	16
7e1046a94a75679fe7ac259e068afdb5	5	5	25

Now we can select specific data subsets, for example jobs with \(x=2\) or \(x^2 > 10\):

df[(df["sp.x"] == 2) | (df["doc.square"] > 10)]

	sp.x	doc.abs	doc.square
3c5a15f6f26125f2902f38ff28a94072	-5	5	25
22749661e1ac649551a29953c93c9e92	-4	4	16
46c24d61c4220f8b62d2ae73d686ec18	2	2	4
9cdfeafe274b4f1762f0bf885ca055b7	4	4	16
7e1046a94a75679fe7ac259e068afdb5	5	5	25

We can plot a graph from our pretend data using matplotlib:

fig, ax = plt.subplots(dpi=120)
df.plot("sp.x", "doc.abs", ax=ax, label="$f(x)=|x|$")
df.plot("sp.x", "doc.square", ax=ax, label="$f(x)=x^2$")
ax.set_xlabel("x")
ax.set_ylabel("f(x)")
plt.show()