# Data Analysis
Combine, transform, and analyze data from multiple runs.
## Combine datasets
```python
import polars as pl
from pyngb import read_ngb
files = ["a.ngb-ss3", "b.ngb-ss3"]
frames = []
for f in files:
t = read_ngb(f)
df = pl.from_arrow(t).with_columns(pl.lit(f).alias("source_file"))
frames.append(df)
combined = pl.concat(frames)
print(combined.shape)
```
## Quick stats
```python
if {'time', 'sample_temperature'} <= set(combined.columns):
stats = combined.select([
pl.col('time').max().alias('duration_s'),
pl.col('sample_temperature').min().alias('min_temp_c'),
pl.col('sample_temperature').max().alias('max_temp_c'),
])
print(stats)
```
Data Analysis
Combine, transform, and analyze data from multiple runs.