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DF

Df is an abbreviation used across disciplines, and its meaning depends on the context. In statistics, df stands for degrees of freedom, a parameter that counts the number of independent pieces of information available to estimate a quantity. It influences the sampling distribution and critical values used in hypothesis tests and confidence intervals. For a single-sample t-test with a sample size n, the degrees of freedom are n − 1. In a chi-squared test with k categories, df = k − 1. In analysis of variance (ANOVA), df are assigned to different sources of variation and contribute to F-statistics.

In calculus, df denotes the differential of a function f, describing an infinitesimal change in f corresponding

In programming and data analysis, df is a common shorthand for a DataFrame, a tabular data structure

Because df has multiple legitimate meanings, its interpretation must be inferred from surrounding text or definitions.

to
a
small
change
in
its
inputs.
For
a
function
of
one
variable,
df
=
f′(x)
dx.
In
several
variables,
the
total
differential
is
df
=
∂f/∂x
dx
+
∂f/∂y
dy
+
…
and
so
on.
Differentials
are
foundational
in
integration,
the
chain
rule,
and
differential
geometry.
that
stores
data
with
rows
and
columns.
It
is
widely
used
in
Python's
pandas
library;
programmers
typically
name
a
DataFrame
object
df.
The
term
is
also
used
informally
in
other
languages
to
refer
to
a
similar
table-like
object.