# Quick Start Guide

```python
%load_ext autoreload
%autoreload 2
```


```python
"""
Quick demonstration of osiris_utils:
• opens an OSIRIS simulation directory
• plots Ez field at t = 2000
Run with:  python examples/quick_start.py  <PATH_TO_RUN>
"""
```


```python
import sys
from pathlib import Path

import matplotlib.pyplot as plt

import osiris_utils as ou

```


```python
sim_path = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("example_data/thermal.1d")
sim = ou.Simulation(sim_path)
```


```python
# grab Ez diagnostic
ez = sim["e3"]
```


```python
# plot Ez field at iteration 220
plt.plot(ez.x, ez[220], label=f"${ez.label}$")
plt.title(rf"${ez.label}$ at t = {ez.time(220)[0]} $[{ez.time(220)[1]}]$")
plt.xlabel(ez.axis[0]["plot_label"])
plt.ylabel(f"${ez.units}$")
plt.legend()
plt.tight_layout()
plt.show()
```